problem-2.9

problem-2.9  This shows the number of doctors with that many awards. The great majority involve just one award
> table(table(npdb$ID))

   1    2    3    4    5    6    8   11   15   22   73
6105  235   12    4    7    1    1    1    1    1    1
> tmp = table(table(npdb$ID))
> sum(tmp[-1])/sum(tmp)         # percent 2 or more
[1] 0.04145