Frequencies for provtype variable in impact1998 dataset :

   Provider |
       Type |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      4,301       83.00       83.00
          7 |         96        1.85       84.85
          8 |         45        0.87       85.72
         16 |        691       13.33       99.05
         17 |         36        0.69       99.75
         21 |          8        0.15       99.90
         22 |          5        0.10      100.00
------------+-----------------------------------
      Total |      5,182      100.00

by Jean Roth , jroth@nber.org , 17 Mar 2016