Frequencies for first 10,000 rows of prov6185 variable in pos2007 dataset :

 srv: shock |
       wave |
lithotripte |
          r |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      8,682       86.82       86.82
          0 |      1,284       12.84       99.66
          1 |          7        0.07       99.73
          2 |         23        0.23       99.96
          3 |          4        0.04      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 17 May 2017