Were the number of defaults sequentially increasing with 2 and 3 defaults in the last 2 rows? I am not sure. May be if we add the prob associated with these 2 it comes out to be more than 5 % and if add just the last row it was less than 5%. Also, I got the explanation wrong in the previous post. Anyways I suppose am imagining different scenarios to defend the answerI thought its was not cumulative default probabilities. I think I got 3k (5k - 2k). I got 5 defaults to reach 95%. Might be wrong though. :/