STATA - Regression with decreasing sample + save t-statistics

#1
Hi all,

I am working with the following data:
stick year q diff_unemploy
2.03 1975 1 0.031
1.28 1976 1 -0.005
0.92 1977 1 -0.002
2.03 1975 2 0.024
1.87 1976 2 -0.005
0.92 1977 2 -0.002
2.03 1975 3 0.031
1.33 1976 3 0.003
0.92 1977 3 -0.002
1.40 1975 4 0.031
1.28 1976 4 0.1
0.92 1977 4 -0.002

I am running the following regression:
by q: regress diff_unemploy stickiness

I would like to create a loop that would execute this regression and reduce the sample by one year at each iteration. I would like to save the regression coefficient and the t-statitics at each iteration.

For example:
first iteration: from 1975 to now -> save: Coef(_cons) Coef(stick) t-stat(_cons) t-stat(stick)

second iteration: from 1976 to now -> save: Coef(_cons) Coef(stick) t-stat(_cons) t-stat(stick)
etc...
up to (now-1 year) to now -> save: Coef(_cons) Coef(stick) t-stat(_cons) t-stat(stick)

Please help! Thanks a lot in advance !