Frequencies for ptype variable in impact2012 dataset :

   Provider |
       Type |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      2,640       75.41       75.41
          7 |        175        5.00       80.41
          8 |         32        0.91       81.32
         14 |        193        5.51       86.83
         15 |         18        0.51       87.35
         16 |        320        9.14       96.49
         17 |        120        3.43       99.91
         21 |          2        0.06       99.97
         22 |          1        0.03      100.00
------------+-----------------------------------
      Total |      3,501      100.00

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