st: fill or expand data

[nicostat@gmail.com]

Dear Statalist,
My question is about to display or fill my data set. I have tried the
command tsfill but I don't know how  continue to arrive at my final
data set.
I have  this data:
id  year enter   year exit    yearcont
1  10/80             2/81           81
1  3/81                4/81          81
1 11/85             2/87          87

And I want to have this one

id  year enter   year exit    yearcont
1  10/80               3/81           80
1   10/80              3/81            81
1   3/81               4/81             81
1   11/85             2/87             85
1    11/85            2/87            86
1  11/85             2/87              87

Thanks for your help.
Catia

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