Hey stata community,

I have a question regarding creating a new variable depending on many other variables.

My dataset looks like this: (You see, there are different products depending on the country, and different sales. Some products are not (yet) on the market (sales=0)).
Country Product Sales 1/2003 Sales 2/2003 Sales 3/2003 Sales 4/2003 Sales 1/2004 Sales 2/2004 Sales 3/2004 Sales 4/2004
Germany Product A 0 0 0 0 0 3 5 7
Germany Product B 0 3 4 0 0 7 8 9
Germany Product C 12 12 12 14 15 17 18 17
Germany Product D 2 5 7 0 0 10 8 7
UK Product A 0 0 0 0 0 2 2 2
UK Product B 0 0 0 2 3 4 5 6
UK Product D 1 1 1 1 1 2 2 2
France Product A 3 4 5 6 6 6 6 7
France Product C 0 0 0 0 1 1 0 0
France Product D 12 13 19 19 34 0 0 0
Spain Product A 1 2 3 4 0 0 7 8
Spain Product B 0 0 0 0 0 1 2 3
Spain Product C 3 4 5 6 7 7 6 0
Spain Product D 0 0 0 0 0 1 2 3
What I need now is a new variable, where it says if a product is on the market 1 year after the product launch, e.g. in Germany Product B entered the market in 2/2003, and has been 4 quarters on the market (sales >0) and is still on the market one year later (in 2/2004). If the product has been at least one year on the market (all 4 quarters are sales >0), I want the variable to say 1, if not, then 0.

Many thanks for your answers!
Best, Milena