Frequencies for first 10,000 rows of prov2520 variable in pos1992 dataset :

srv: speech |
    therapy |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      8,768       87.68       87.68
          0 |        321        3.21       90.89
          1 |        373        3.73       94.62
          2 |        449        4.49       99.11
          3 |         89        0.89      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 26 Jan 2016