Frequencies for first 10,000 rows of prov2520 variable in pos1999 dataset :

srv: speech |
    therapy |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      8,564       85.64       85.64
          0 |        246        2.46       88.10
          1 |        318        3.18       91.28
          2 |        650        6.50       97.78
          3 |        222        2.22      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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