Try to find out what may cause Nullpointer Exception in line 10 of your code, what could be null there? Also, why do you think line 7 will help in skipping lines 8-18.
Try to test your line 7 if condition with values 1992, 1995 and 2010.
I believe you are assuming that nobelPrizeWinners.get(year) will give proper value for years 1993-2009.
If I become filthy rich, I'll sponsor research for painless dental treatment at Harvard Medical School. Thats why,I'm learning Java.I have 32 teeth, 22 are man made.