xtabond2 data issue

Today, 09:05
I'm using panel data and xtabond2 command in STATA 15.1. I'm trying to find firm's Capital expenditure by using the formula (change in fixed assets + depreciation). My problem is that all my previous data is quarterly but the depreciation variable is half annual. I have merged the depreciation value with my existing data, however, when I try to run the GMM command using the one year lagged value of capital expenditure as dependent variable, the output shows only 360 observations out of the 1903 observations.
1. Is it possible to convert the depreciation variable into quarterly values?
2. If not how do I run the xtabond2 command?

nput long stockcode str10 accountingperiod float(depreciationoffixedassets roa infrainv)
2 "31/03/2005" 11621294 . 0
2 "30/06/2005" 18675032 . 0
2 "30/09/2005" 27717452 .0619048 0
2 "31/12/2005" 38351772 .0909091 0
2 "31/03/2006" 10274102 .02375 0
2 "30/06/2006" 24649352 .062069 0
2 "30/09/2006" 29365094 .047619 0
2 "31/12/2006" 51678328 .0693878 0
2 "31/03/2007" . .0166 0
2 "30/06/2007" 31763144 .0390625 0
2 "30/09/2007" . .0315789 0
2 "31/12/2007" 108228056 .076 0
2 "31/03/2008" . .0090909 0
2 "30/06/2008" 37646528 .03 0
2 "30/09/2008" . .0316667 0
2 "31/12/2008" 94169016 .0525 0
2 "31/03/2009" . .0092308 0
2 "30/06/2009" 47406276 .0323077 0
2 "30/09/2009" . .0384615 0
2 "31/12/2009" 95653216 .0614286 0
2 "31/03/2010" . .0106667 0
2 "30/06/2010" 51869244 .025625 0
2 "30/09/2010" . .0268421 0
2 "31/12/2010" 95989560 .0545455 0
2 "31/03/2011" . .0070833 0
2 "30/06/2011" 51484288 .0173077 0
2 "30/09/2011" . .0203571 0
2 "31/12/2011" 113447760 .0533333 0
2 "31/03/2012" . .0067742 0
2 "30/06/2012" 62907876 .0181818 0
2 "30/09/2012" . .0234286 0
2 "31/12/2012" 154565120 .0552632 0
2 "31/03/2013" . .0057143 0
2 "30/06/2013" 70018600 .0165116 .000473107
2 "30/09/2013" . .0217391 .0021746522
2 "31/12/2013" 153444256 .05 0
2 "31/03/2014" . .004 0
2 "30/06/2014" 170328480 .0142 0
2 "30/09/2014" . .0188462 0
2 "31/12/2014" 376028608 .0490196 0
2 "31/03/2015" . .0022642 0
2 "30/06/2015" 258810384 .0162963 0
2 "30/09/2015" . .0210526 0
2 "31/12/2015" 490161216 .0557377 0
2 "31/03/2016" . .0025758 0
2 "30/06/2016" 277351936 .0140845 0
2 "30/09/2016" . .0210526 0
2 "31/12/2016" 708210240 .046988 0
2 "31/03/2017" . .0017978 0
2 "30/06/2017" 564830848 .0150538 0
2 "30/09/2017" . .021 0
2 "31/12/2017" 1101115392 .0425 0
2 "31/03/2018" . .0025 0
18 "31/03/2005" 4304813 . 0
18 "30/06/2005" 9176289 . 0
18 "30/09/2005" 13283020 -.0428571 0
18 "31/12/2005" 19062916 -.09 0
18 "31/03/2006" 4038553 -.0079167 0
18 "30/06/2006" 8634199 -.0266667 0
18 "30/09/2006" 13721648 -.0568182 0
18 "31/12/2006" 17075400 .0511111 0
18 "31/03/2007" . -.0657895 0
18 "30/06/2007" 4185665 -.1058824 0
18 "30/09/2007" . -.1882353 0
18 "30/09/2015" . .0842105 0
18 "31/12/2015" 3522850 .1075 .4057575
18 "31/03/2016" . .0211111 .4282978
18 "30/06/2016" 1119746.8 .0413793 .3432983
18 "30/09/2016" . .0553846 .2362846
18 "31/12/2016" 8868948 .07 0
18 "31/03/2017" . .0144578 .08292771
18 "30/06/2017" 6270470 .0357895 .08605894
18 "30/09/2017" . .051 .087425
18 "31/12/2017" 17923018 .0425 0
18 "31/03/2018" . .0208333 0
27 "31/03/2005" 232184064 .0295455 0
27 "30/06/2005" 466714304 .0617021 0
27 "30/09/2005" 663135296 .1023256 0
27 "31/12/2005" 523403552 .1586957 0
27 "31/03/2006" . .03125 0
27 "30/06/2006" 249541984 .0596154 0
27 "30/09/2006" 372889568 .1195652 0
27 "31/12/2006" 574306880 .16 0
27 "31/03/2007" . -.0022 0
27 "30/06/2007" 279865472 .0021569 0
27 "31/12/2007" 1029741760 .1 0
27 "31/03/2008" . .0023684 0
27 "30/06/2008" 528499392 .038 0
27 "30/09/2008" . .06 .81905
27 "31/12/2008" 1018059392 .07 0
27 "31/03/2009" . -.0000427 0
27 "30/06/2009" 483738240 .0255 0
27 "30/09/2009" . .055 0
27 "31/12/2009" 1199740160 .0447368 0
27 "31/03/2010" . .0052632 0
27 "30/06/2010" 575846144 .05 0
27 "30/09/2010" . .0684211 0
27 "31/12/2010" 1232957184 .0684211 0
27 "31/03/2011" . .0002316 0
27 "30/06/2011" 655092032 .0128571 0
end
[/CODE]


GMM result:

xtabond2 Dominv l.Dominv l.infrainv yr2005-yr2018 ind1-ind8, gmm (infrainv, lag(3 6) collapse) iv(yr2005-yr2018 ind1-ind8, eq(level)) ro
> bust small nodiffsargan pca
Favoring speed over space. To switch, type or click on mata: mata set matafavor space, perm.
Warning: Two-step estimated covariance matrix of moments is singular.
Using a generalized inverse to calculate robust weighting matrix for Hansen test.

Dynamic panel-data estimation, one-step system GMM
------------------------------------------------------------------------------
Group variable: i Number of obs = 372
Time variable : quarterly_~e Number of groups = 56
Number of instruments = 9 Obs per group: min = 5
F(24, 55) = 392.41 avg = 6.64
Prob > F = 0.000 max = 5
------------------------------------------------------------------------------
| Robust
Dominv | Coef. Std. Err. t P>|t| [95% Conf. Interval]
-------------+----------------------------------------------------------------
Dominv |
L1. | 2.734951 4.259249 0.64 0.523 -5.800775 11.27068
|
infrainv |
L1. | .0708712 .0100792 7.03 0.000 .0506721 .0910704
|
yr2005 | 0 (omitted)
yr2006 | -8.796221 13.09005 -0.67 0.504 -35.02927 17.43682
yr2007 | -8.911447 13.25616 -0.67 0.504 -35.47738 17.65449
yr2008 | -8.899824 13.22639 -0.67 0.504 -35.4061 17.60645
yr2009 | 0 (omitted)
yr2010 | 0 (omitted)
yr2011 | 0 (omitted)
yr2012 | 0 (omitted)
yr2013 | 0 (omitted)
yr2014 | 0 (omitted)
yr2015 | 0 (omitted)
yr2016 | 0 (omitted)
yr2017 | -8.727481 12.9548 -0.67 0.503 -34.68948 17.23452
yr2018 | 0 (omitted)
ind1 | 0 (omitted)
ind2 | 0 (omitted)
ind3 | -1.096275 1.624836 -0.67 0.503 -4.35252 2.159969
ind4 | 0 (omitted)
ind5 | 0 (omitted)
ind6 | 0 (omitted)
ind7 | -4.435383 6.599573 -0.67 0.504 -17.66122 8.790457
ind8 | 0 (omitted)
_cons | 8.834959 13.0945 0.67 0.503 -17.40701 35.07693
------------------------------------------------------------------------------
Instruments for first differences equation
GMM-type (missing=0, separate instruments for each period unless collapsed)
L(3/6).infrainv collapsed
Instruments for levels equation
Standard
yr2005 yr2006 yr2007 yr2008 yr2009 yr2010 yr2011 yr2012 yr2013 yr2014
yr2015 yr2016 yr2017 yr2018 ind1 ind2 ind3 ind4 ind5 ind6 ind7 ind8
_cons
GMM-type (missing=0, separate instruments for each period unless collapsed)
DL2.infrainv collapsed
------------------------------------------------------------------------------
Arellano-Bond test for AR(1) in first differences: z = 0.03 Pr > z = 0.974
Arellano-Bond test for AR(2) in first differences: z = -0.67 Pr > z = 0.505
------------------------------------------------------------------------------
Sargan test of overid. restrictions: chi2(-16) = 0.00 Prob > chi2 = .
(Not robust, but not weakened by many instruments.)
Hansen test of overid. restrictions: chi2(-16) = 0.27 Prob > chi2 = .
(Robust, but weakened by many instruments.)
------------------------------------------------------------------------------
Extracted 2 principal components from GMM-style instruments
Portion of variance explained by the components = 0.520
Kaiser-Meyer-Olkin measure of sampling adequacy = 0.453