Frequencies for first 10,000 rows of proc23 variable in nhamcsed1998 dataset :

      other |
  procedure |
 #2 - 3 dgt |      Freq.     Percent        Cum.
------------+-----------------------------------
        000 |      9,970       99.70       99.70
        280 |          1        0.01       99.71
        349 |          1        0.01       99.72
        372 |          1        0.01       99.73
        389 |          2        0.02       99.75
        452 |          1        0.01       99.76
        890 |          1        0.01       99.77
        891 |          1        0.01       99.78
        893 |          3        0.03       99.81
        896 |          1        0.01       99.82
        909 |          2        0.02       99.84
        919 |          3        0.03       99.87
        938 |          1        0.01       99.88
        943 |          2        0.02       99.90
        944 |          7        0.07       99.97
        954 |          1        0.01       99.98
        963 |          1        0.01       99.99
        966 |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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