Frequencies for first 10,000 rows of prov1570 variable in pos1997 dataset :

participati |
on medicare |
     opt/sp |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      9,933       99.33       99.33
          N |         64        0.64       99.97
          Y |          3        0.03      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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