dummy1 gen dummy2 yr dummy3
1  Glenn 1318   2  63117  3   3719
2  Ray   2917   2  41723  2   2913
3  Paula 3306   1  67701  1   4000
4  Tom   2737   2  60227  4   3931
5  Albert3102   2  51315  1   3227
6  Louise6162   1  73209  2   3511
7  Janet 7643   1  61103  2   3823
8  Barry 8921   2  63217  3   3115
9  Annie 2317   1  41723  1   3921
10 Jack  1093   1  60227  4   3714
11 Cindy 8567   1  67456  2   3432
12 David 6545   2  64534  2   2988
   gen yr
1    2  3
2    2  2
3    1  1
4    2  4
5    2  1
6    1  2
7    1  2
8    2  3
9    1  1
10   1  4
11   1  2
12   2  2
   yr
gen 1 2 3 4
  1 2 3 0 1
  2 1 2 2 1