Frequencies for s5_c1_21 variable in hcris2552_10_2017 dataset :

        mcp |
  physician |
    payment |
     method |
      (y/n) |
    s500000 |
02100 00100 |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      3,608       96.24       96.24
          X |        141        3.76      100.00
------------+-----------------------------------
      Total |      3,749      100.00

by Jean Roth , jroth@nber.org , 25 Oct 2018