Frequencies for first 10,000 rows of prov1570 variable in pos1998 dataset :

participati |
on medicare |
     opt/sp |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      9,942       99.42       99.42
          N |         57        0.57       99.99
          Y |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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