Frequencies for first 10,000 rows of proc5 variable in nhamcsopd1994 dataset :

 service #5 |
  procedure |
   code - 4 |
     digits |      Freq.     Percent        Cum.
------------+-----------------------------------
       0000 |      9,977       99.77       99.77
       1621 |          1        0.01       99.78
       4513 |          1        0.01       99.79
       5794 |          1        0.01       99.80
       8703 |          1        0.01       99.81
       8826 |          1        0.01       99.82
       8839 |          1        0.01       99.83
       8876 |          1        0.01       99.84
       8908 |          1        0.01       99.85
       8909 |          1        0.01       99.86
       8926 |          1        0.01       99.87
       8936 |          1        0.01       99.88
       8939 |          1        0.01       99.89
       8952 |          2        0.02       99.91
       8959 |          1        0.01       99.92
       9142 |          2        0.02       99.94
       9146 |          1        0.01       99.95
       9199 |          1        0.01       99.96
       9439 |          1        0.01       99.97
       9526 |          1        0.01       99.98
       9999 |          2        0.02      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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