Frequencies for first 10,000 rows of othproc4 variable in nhamcsopd2007 dataset :

procedure 4 |      Freq.     Percent        Cum.
------------+-----------------------------------
         -9 |      9,992       99.92       99.92
       0392 |          1        0.01       99.93
       0689 |          1        0.01       99.94
       8521 |          1        0.01       99.95
       8628 |          1        0.01       99.96
       9339 |          1        0.01       99.97
       9509 |          2        0.02       99.99
       9787 |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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