Frequencies for first 10,000 rows of proc5per variable in nhamcsopd1993 dataset :

 service #5 |
  performed |
 or ordered |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,962       99.62       99.62
          1 |         26        0.26       99.88
          2 |         11        0.11       99.99
          3 |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 28 Mar 2016