Dear Stata Members
I would like to calculate the industry sales growth (isg) and following is my sample data


Code:
clear
input str9 firm int year byte ind_dum float netsales
"4DS.AX"   2015 31 7.70e-06
"PRS.AX"   2015 21        .
"HRN.AX"   2015 21        .
"VIC.AX"   2015 21  .000139
"PVW.AX"   2015 21        0
"ALX.AX"   2015 23  1.88932
"FBR.AX"   2015 31  .174572
"IPT.AX"   2015 21  .927405
"ODM.AX"   2015 21  .018043
"ABV.AX"   2015 31  5.31421
"SRK.AX"   2015 21  .193432
"KLO.AX"   2015 23  13.2431
"GLA.AX"   2015 21  .009091
"EOS.AX"   2015 31  22.1893
"BLY.AX"   2015 21  735.158
"AGR.AX"   2015 21  .030962
"DRE.AX"   2015 21  .015323
"LLC.AX"   2015 23  10231.6
"NZS.AX"   2015 31  .477879
"TPD.AX"   2015 21  .298108
"HGO.AX"   2015 21  101.487
"AWV.AX"   2015 21  .016317
"ALT.AX"   2015 31  .862368
"IMC.AX"   2015 31  .865704
"SYA.AX"   2015 21  .016271
"TNR.AX"   2015 21        0
"FLC.AX"   2015 31   .00118
"NWC.AX"   2015 21  .034922
"ADR.AX"   2015 31  2.21078
"AAP.AX"   2015 11   2.6729
"HPP.AX"   2015 31  54.7183
"CIO.AX"   2015 31        0
"AGD.AX"   2015 21  62.4951
"BMN.AX"   2015 21   .05778
"TGN.AX"   2015 21  .120552
"PXX.AX"   2015 21  .002889
"RIO.AX"   2015 21    34829
"AJQ.AX"   2015 21  .075345
"PDI.AX"   2015 21  .007142
"PSA.AX"   2015 21    1.613
"GGG.AX"   2015 21  .141135
"CCE.AX"   2015 22  1.25232
"PDZ.AX"   2015 21  .026895
"CRR.AX"   2015 21   .14729
"PPG.AX"   2015 31  187.885
"AQX.AX"   2015 21  .000917
"EUR.AX"   2015 21  .003143
"SVL.AX"   2015 21  .002712
"CCZ.AX"   2015 21  .004715
"FNT.AX"   2015 21  .015054
"LRL.AX"   2015 21  .001579
"TMS.AX"   2015 21        .
"SIH.AX"   2015 21  .001418
"APG.AX"   2015 21        .
"CNJ.AX"   2015 21  .000855
"EMU.AX"   2015 21  .166837
"XAM.AX"   2015 21  .026918
"FIN.AX"   2015 21        .
"CLA.AX"   2015 21  .002042
"GUD.AX"   2015 31  382.961
"DYL.AX"   2015 21  .097517
"DEV.AX"   2015 21        .
"AAU.AX"   2015 21  46.6495
"JAL.AX"   2015 21  .012966
"AAR.AX"   2015 21        0
"GLV.AX"   2015 21  .164472
"AZS.AX"   2015 21  .275887
"LCL.AX"   2015 21  .003237
"SFX.AX"   2015 21  .164811
"LEG.AX"   2015 21  .418429
"LCD.AX"   2015 21  .008343
"ADD.AX"   2015 21        0
"BSR.AX"   2015 21  .015278
"BKW.AX"   2015 31   528.38
"NVA.AX"   2015 21        0
"IDA.AX"   2015 21  2.86434
"PPY.AX"   2015 31  .068049
"EQR.AX"   2015 21  .040662
"HE8.AX"   2015 21        .
"KRR.AX"   2015 21  .003197
"ARD.AX"   2015 21        .
"SES.AX"   2015 31  13.8294
"SAN.AX"   2015 21     .047
"BNR.AX"   2015 21  .021363
"MSV.AX"   2015 21  19.3945
"CEL.AX"   2015 21  .044144
"MPR.AX"   2015 22  41.8527
"DEM.AX"   2015 22  .528381
"AS1.AX"   2015 11  1.25869
"LTR.AX"   2015 21  .383828
"VML.AX"   2015 21  .035893
"WNR.AX"   2015 31  2.20463
"MLM.AX"   2015 21  .552067
"MGT.AX"   2015 21  .056362
"DDD.AX"   2015 21   .00785
"XRF.AX"   2015 31  15.9248
"A3D.AX"   2015 31        .
"GLN.AX"   2015 21  .021841
"OKJ.AX"   2015 31  .011024
"FWD.AX"   2015 31  210.239
"RIC.AX"   2015 31  699.422
"ZEU.AX"   2015 21  .137385
"RFG.AX"   2015 31  190.477
"MNB.AX"   2015 21   .00235
"MXC.AX"   2015 31  .004538
"GMRDD.AX" 2015 21  .019976
"ERA.AX"   2015 21  253.359
"NXM.AX"   2015 21        0
"WC8.AX"   2015 21  .001402
"CZR.AX"   2015 21  .007365
"ESS.AX"   2015 21  .201089
"AYM.AX"   2015 21  .037542
"MYL.AX"   2015 21  .166144
"KOV.AX"   2015 31  48.5543
"ZGL.AX"   2015 31  92.6665
"AUH.AX"   2015 21  .013012
"VMS.AX"   2015 21  .134612
"BUY.AX"   2015 21  1.49285
"GAP.AX"   2015 31  114.014
"CRB.AX"   2015 21  .065337
"BRI.AX"   2015 31  123.384
"GW1.AX"   2015 21  .098519
"BUX.AX"   2015 21  .011232
"ECS.AX"   2015 31  4.54599
"WSI.AX"   2015 23  .000116
"88E.AX"   2015 21  .010549
"AJY.AX"   2015 21  1.93232
"E25.AX"   2015 21  .334176
"ERL.AX"   2015 21  .003112
"SI6.AX"   2015 21  .055345
"CSL.AX"   2015 31     5628
"ATL.AX"   2015 31  72.7194
"BKL.AX"   2015 31  363.331
"MBK.AX"   2015 21  .004946
"PBX.AX"   2015 21  .038497
"MVL.AX"   2015 21        0
"ANW.AX"   2015 21  .001009
"EGR.AX"   2015 31  .038173
"NWF.AX"   2015 21   .05033
"PEN.AX"   2015 21     .153
"WPL.AX"   2015 21     5030
"DRX.AX"   2015 21  .111577
"SGC.AX"   2015 21  .270732
"GLL.AX"   2015 21  .615548
"IBG.AX"   2015 21  .196452
"EMP.AX"   2015 21  .287859
"SKS.AX"   2015 23  2.71821
"PEK.AX"   2015 21  .029606
"AWN.AX"   2015 22   3.6738
"M7T.AX"   2015 31  .128718
"AUZ.AX"   2015 21        .
"TIE.AX"   2015 21        .
"EVN.AX"   2015 21  513.053
"COI.AX"   2015 21  .593977
"TON.AX"   2015 21  .000546
"AOP.AX"   2015 21  .016479
"FHS.AX"   2015 21  .000755
"PNV.AX"   2015 31   .10841
"AEV.AX"   2015 21  .550018
"BXB.AX"   2015 31   5440.5
"CGB.AX"   2015 31  .131854
"RSG.AX"   2015 21   381.81
"ASQ.AX"   2015 21  1.22065
"FFI.AX"   2015 31   23.669
"EL8.AX"   2015 21  .289801
"MWY.AX"   2015 31  109.614
"AQI.AX"   2015 21   .01681
"PRX.AX"   2015 21  .302281
"RR1.AX"   2015 21  .005855
"EGY.AX"   2015 31  8.32588
"RNX.AX"   2015 21  .012149
"FML.AX"   2015 21  1.82021
"RPG.AX"   2015 23        0
"CHK.AX"   2015 31  .010146
"MCE.AX"   2015 31  110.995
"AFR.AX"   2015 21    .0705
"HLX.AX"   2015 21  .055592
"GSN.AX"   2015 21  .030639
"VRX.AX"   2015 21  .047102
"GED.AX"   2015 21  .131484
"GOR.AX"   2015 21  .770753
"BMG.AX"   2015 21  .003821
"BLG.AX"   2015 31  2.72176
"GIB.AX"   2015 21   .07533
"ADN.AX"   2015 21  .036463
"ECT.AX"   2015 21  .009676
"ZIM.AX"   2015 21  408.391
"CCJ.AX"   2015 21  .011348
"MAT.AX"   2015 21  1.51972
"WMC.AX"   2015 21  .009707
"BAS.AX"   2015 21  .057037
"TNP.AX"   2015 21  .004053
"TZN.AX"   2015 21        0
"KAR.AX"   2015 21   1.6671
"TTT.AX"   2015 31        0
"CAE.AX"   2015 21  .005971
"AIS.AX"   2015 21  167.395
"STO.AX"   2015 21     2442
"CZN.AX"   2015 21  1.08749
"E79.AX"   2015 21  .074582
"CGN.AX"   2015 21   .04392
"MGX.AX"   2015 21  252.577
"FMG.AX"   2015 21     8574
"AVA.AX"   2015 31   14.371
"RAN.AX"   2015 31   .34746
"CYC.AX"   2015 31   9.1874
"ENR.AX"   2015 21  1.23003
"TOE.AX"   2015 21  .382333
"KPO.AX"   2015 22  .775005
"SYR.AX"   2015 21     .291
"GCR.AX"   2015 21  .030816
"AKN.AX"   2015 21  .031552
"MBH.AX"   2015 31  .007951
"RDN.AX"   2015 21  43.7964
"FAU.AX"   2015 21  .004569
"CHN.AX"   2015 21  .468602
"MML.AX"   2015 21  123.172
"NCR.AX"   2015 21  .396755
"BLU.AX"   2015 21  .161784
"EYE.AX"   2015 31  48.2909
"GLB.AX"   2015 31  106.131
"OBM.AX"   2015 21  .001872
"ARR.AX"   2015 21  .003944
"SKY.AX"   2015 21  .244236
"ICG.AX"   2015 21  .026116
"SGQ.AX"   2015 21  .016047
"INA.AX"   2015 23  58.5664
"STX.AX"   2015 21  2.07699
"AGS.AX"   2015 21  .170589
"TNG.AX"   2015 21        .
"OKU.AX"   2015 21  .505905
"CMM.AX"   2015 21  .214625
"PO3.AX"   2015 22        0
"AME.AX"   2015 21  .026317
"NMT.AX"   2015 21  .323205
"BDC.AX"   2015 21  .086285
"MAN.AX"   2015 21  2.41912
"PGM.AX"   2015 21  .013397
"KGM.AX"   2015 21  .007165
"DAF.AX"   2015 21  .001071
"ING.AX"   2015 11   1740.1
"RXM.AX"   2015 21        .
"KFE.AX"   2015 21   .01047
"PTX.AX"   2015 31  .030793
"ENT.AX"   2015 21  .012742
"GES.AX"   2015 21   .00077
"VAR.AX"   2015 21  .206112
"CYL.AX"   2015 21  .015516
"CMP.AX"   2015 31  25.8045
"SIX.AX"   2015 31  .973876
end

Code:
encode firm, gen (id)

xtset id year

Panel variable: id (strongly balanced)
 Time variable: year, 2015 to 2015
         Delta: 1 unit


 by ind_dum year, sort:  gen isg = d.netsales /l.netsales                                   
not sorted
r(5);

*I also tried 
bysort ind_dum (year): gen isg = d.netsales /l.netsales
not sorted
r(5);
Why is Stata repeatedly saying not sorted?