You want to find the first positive value in column D

in B29
=INDEX($A4:$A9,MATCH(TRUE,D4:D9>0,0),0)
Note: Array formula, use Ctrl-Shift-Enter

Copy to C29

In the event you want to put actual years in these cells you should format B29 C29 to general as the format contains a comma, proper years e.g. 2012 appear as 2,012 in these cells