Dear Statalist,

I tried to find the thread of missing data treatment in STATA but I could not find it. If someone has had the same question about this before, please kindly help me to post the link and happy to delete this thread.
I have questions regarding the missing data treatment in STATA for unbalanced panel data. I have unbalanced panel data for the period 2006 - 2017 with 5 variables. There are some years of some individual data that only have less than 5 variables, in that case:
1. how do I treat the missing data whether I need to put zero or leave it blank?
2. Whether put zero or leave it blank affect the number of observations?

What is the suggestion to treat this missing data? Here I list some of my datasets. The blank spot is the missing data.
Some years of ID has no data, do I need to take it off from my data or leave it blank or zero?

Code:
ID Year ROA RD Intensity Leverage SIZE
ATM.AX 2017 0.05018 0.00593 0.38395 9.45276
ATM.AX 2016 0.02428 0.00573 0.38600 9.48925
ATM.AX 2015 0.00314 0.00360 0.39662 9.48102
ATM.AX 2014 0.03123 0.00312 0.45238 9.33767
ATM.AX 2013 0.05913 0.00711 0.41489 9.30480
ATM.AX 2012 0.08257 0.00865 0.34890 9.29429
ATM.AX 2011 0.18975 0.00940 0.29137 9.21509
ATM.AX 2010 0.23416 0.01478 0.21568 9.12382
ATM.AX 2009 0.13495 0.00739 0.17878 9.06997
ATM.AX 2008 0.24983 0.01419 0.21297 9.12548
ATM.AX 2007 0.60715 0.00504 0.27347 9.16574
ATM.AX 2006 0.39480 0.00567 0.41285 9.01221
CGM.AX 2017 - 0.35130 3.24652 6.26208
CGM.AX 2016 - 0.52461 4.40949 6.01259
CGM.AX 2015 - 2.31306 2.22907 6.19635
CGM.AX 2014 - 0.43015 0.50321 6.69391
CGM.AX 2013 - 0.19008 0.78025 6.72938
CGM.AX 2012 - 0.02078 0.23537 7.23147
CGM.AX 2011 0.43734 0.20769 7.13459
CGM.AX 2010 - 0.15499 0.26446 0.22807 6.97070
CGM.AX 2009 - 0.13175 0.32719 6.94133
CGM.AX 2008 - 0.02141 0.63914 0.22383 6.94586
CGM.AX 2007 - 0.14034 10.80597 0.08406 6.92174
CGM.AX 2006 0.42961 0.37287 0.08025 6.85449
CDT.AX 2017 - 1.34157 109.61333 0.94394 5.53619
CDT.AX 2016 - 1.24766 95.94615 2.34886 5.38998
CDT.AX 2015 - 0.78376 60.82037 0.90781 5.67502
CDT.AX 2014 - 0.33934 40.87309 0.18513 5.94838
CDT.AX 2013 - 0.21600 17.59932 0.07845 6.36504
CDT.AX 2012 - 0.12898 11.43324 0.14042 6.62093
CDT.AX 2011 - 0.01636 10.52734 0.11270 6.94857
CDT.AX 2010 - 0.07897 15.32129 0.11668 6.89607
CDT.AX 2009 - 0.74828 19.32075 0.11954 5.93952
CDT.AX 2008 - 0.16633 11.89941 0.07615 6.17522
CDT.AX 2007 - 0.16301 13.50769 0.05610 6.39094
CDT.AX 2006 - 0.04072 10.54762 0.08028 6.53631
ACS.AX 2017 - 0.07611 0.70817 6.80636
ACS.AX 2016 - 0.07500 0.33179 0.49811 6.82299
ACS.AX 2015 - 0.13106 31.48739 0.04227 6.68935
ACS.AX 2014 - 0.03868 14.71475 0.01227 7.27406
ACS.AX 2013 - 0.03229 0.01363 7.33274
ACS.AX 2012 - 0.07118 0.01272 7.34673
ACS.AX 2011 - 0.03968 0.00872 7.34515
ACS.AX 2010 - 0.08017 0.06501 0.03051 7.23339
ACS.AX 2009 - 0.04066 2.17783 0.01876 7.08472
ACS.AX 2008 - 0.05734 0.24290 0.05078 7.14192
ACS.AX 2007 - 0.10324 3.48837 0.02731 6.65360
ACS.AX 2006 - 0.06944 0.50633 0.04601 6.67560
MTB.AX 2017 - 0.46659 4.31521 5.91632
MTB.AX 2016 - 1.48764 18.66129 5.25057
MTB.AX 2015 - 33.69375 156.65259 4.27207
MTB.AX 2014 - 33.54684 97.25403 4.36078
MTB.AX 2013 - 1.49375 3.09969 5.71634
MTB.AX 2012 - 0.05620 0.08268 7.17762
MTB.AX 2011 - 0.06945 359.63636 0.04685 7.17107
MTB.AX 2010 - 0.05665 0.03956 7.16164
MTB.AX 2009 - 0.05762 0.01507 7.17598
MTB.AX 2008 - 0.06749 0.01717 7.18021
MTB.AX 2007 - 0.08237 0.00842 7.13152
MTB.AX 2006 - 0.07369 0.01274 7.12516
RBX.AX 2017 - 0.67787 0.57170 1.41164 6.05710
RBX.AX 2016 - 0.53093 1.06794 6.07142
RBX.AX 2015 - 0.27682 0.61718 6.26085
RBX.AX 2014 0.59806 0.65958 6.55228
RBX.AX 2013 0.03015 0.82058 6.61416
RBX.AX 2012 - 0.07778 0.17023 6.98062
RBX.AX 2011 - 0.06555 0.17739 6.84316
RBX.AX 2010 - 0.07915 0.18446 6.86146
RBX.AX 2009 - 0.18015 0.18693 6.82210
RBX.AX 2008 - 0.13902 0.15665 6.88098
RBX.AX 2007 - 0.14644 0.39943 6.24428
RBX.AX 2006
AKN.AX 2017 - 2.21257 9.37860 0.65464 5.71814
AKN.AX 2016 - 0.42054 10.84888 0.04111 6.35441
AKN.AX 2015 - 0.24696 8.49135 0.07540 6.67257
AKN.AX 2014 - 0.05663 5.50973 0.06334 7.16439
AKN.AX 2013 - 0.09448 1.93775 0.19924 7.30691
AKN.AX 2012 - 0.11980 0.67456 0.06165 7.23711
AKN.AX 2011 - 0.06847 0.36629 0.02397 7.28684
AKN.AX 2010 - 0.15152 0.99484 0.05889 6.86693
AKN.AX 2009 - 0.11908 0.08859 6.79574
AKN.AX 2008 - 0.06196 0.04093 6.82752
AKN.AX 2007 - 0.05565 0.00892 5.65072
AKN.AX 2006 - 0.02909 0.01091 5.43933
MRR.AX 2017 - 0.41977 12.77106 0.03207 6.06567
MRR.AX 2016 - 0.86230 7.58261 0.09964 5.95268
MRR.AX 2015 - 0.28658 7.83351 0.01687 6.19640
MRR.AX 2014 - 0.18326 0.01228 6.36798
MRR.AX 2013 - 0.10291 0.02852 0.01068 6.44262
MRR.AX 2012 - 0.07261 2.82760 0.00668 6.48504
MRR.AX 2011 0.03515 5.24366
MRR.AX 2010
MRR.AX 2009
MRR.AX 2008
MRR.AX 2007
MRR.AX 2006
TRM.AX 2017 - 0.00422 0.09956 6.91081
TRM.AX 2016 - 0.00851 0.06882 0.08899 6.89308
TRM.AX 2015 - 0.02591 1.28617 0.11003 6.88303
TRM.AX 2014 - 0.03620 0.09821 6.87623
TRM.AX 2013 - 0.02435 0.62122 0.03535 6.86844
TRM.AX 2012 0.00418 0.06506 0.04045 6.87061
TRM.AX 2011 0.04336 0.04025 6.82295
TRM.AX 2010 0.05312 0.16829 0.05570 6.62582
TRM.AX 2009 - 0.10229 0.59130 0.04418 6.52697
TRM.AX 2008 - 0.06111 1.16660 0.03922 6.56055
TRM.AX 2007 - 0.07484 0.00379 6.51358
TRM.AX 2006 - 0.21166 0.00648 5.66558
SHK.AX 2017 - 0.14767 3.02297 7.23899
SHK.AX 2016 - 0.07280 2.12392 7.35471
SHK.AX 2015 - 0.11958 1.94563 7.34713
SHK.AX 2014 - 0.40082 1.68499 7.36349
SHK.AX 2013 - 0.24143 0.15239 1.13386 7.32706
SHK.AX 2012 - 0.14063 0.01212 0.55371 7.42744
SHK.AX 2011 0.10056 0.00545 0.65543 7.49603
SHK.AX 2010 - 0.14991 0.02313 0.25847 7.54994
SHK.AX 2009 - 0.06999 14.89601 0.06047 7.25310
SHK.AX 2008 - 0.03764 0.01818 7.27437
SHK.AX 2007 - 0.01666 0.01383 7.22076
SHK.AX 2006 0.04023 0.05745 7.06288
MMG.AX 2017 0.13883 0.91809 10.27781
MMG.AX 2016 0.06050 0.93234 10.32446
MMG.AX 2015 0.02870 0.95453 10.30430
MMG.AX 2014 0.05715 0.87500 10.21790
MMG.AX 2013 0.16039 0.65408 9.72055
MMG.AX 2012 0.16209 0.66398 9.64239
MMG.AX 2011 0.26854 0.02872 0.58436 9.52860
MMG.AX 2010 0.29721 0.02891 0.86241 9.53121
MMG.AX 2009 0.12214 0.00612 0.63062 9.53984
MMG.AX 2008 0.04663 0.31626 9.21098
MMG.AX 2007 0.10341 0.27585 9.10573
MMG.AX 2006 0.20649 0.47994 9.12186
KGD.AX 2017 - 0.07527 0.00800 6.99974
KGD.AX 2016 - 0.01410 0.05045 7.55888
KGD.AX 2015 - 0.01947 0.01003 7.62825
KGD.AX 2014 - 0.02176 0.00987 7.84639
KGD.AX 2013 - 0.01517 0.02718 8.06246
KGD.AX 2012 - 0.02362 52.75198 0.01679 8.05634
KGD.AX 2011 - 0.00976 0.02900 8.14750
KGD.AX 2010 - 0.03316 0.03259 8.08258
KGD.AX 2009 0.02380 7.78115
KGD.AX 2008 - 0.01001 0.02954 7.79492
KGD.AX 2007
KGD.AX 2006
E3S.AX 2017 48.76815 4.38453
E3S.AX 2016 5.54055 5.43772
E3S.AX 2015 0.00324 2.35849 1.83557 5.88703
E3S.AX 2014 0.06687 26.14904 0.92771 5.91031
E3S.AX 2013 1.38957 40.73786 0.52644 5.99307
E3S.AX 2012 0.18993 0.23310 0.03875 6.35597
E3S.AX 2011 0.05319 6.56573
E3S.AX 2010 0.24573 6.39863
E3S.AX 2009 - 0.27949 0.02500 0.17656 6.43616
E3S.AX 2008 - 0.08384 17.55000 0.09748 6.80489
E3S.AX 2007 - 0.06442 6.37931 0.12511 6.75089
E3S.AX 2006 - 0.03660 0.16215 6.95236
Look forward to helping me with this from the STATAlist forum.

Thanks,

Annur