Frequencies for ptype variable in impact2010 dataset :

   Provider |
       Type |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      2,729       75.89       75.89
          7 |        187        5.20       81.09
          8 |         33        0.92       82.01
         14 |        186        5.17       87.18
         15 |         15        0.42       87.60
         16 |        337        9.37       96.97
         17 |        106        2.95       99.92
         21 |          3        0.08      100.00
------------+-----------------------------------
      Total |      3,596      100.00

by Jean Roth , jroth@nber.org , 16 Dec 2016