Frequencies for first 10,000 rows of scopewi2 variable in nhamcsopd2003 dataset :

      scope |
  procedure |
write-in #2 |
  - 4 digit |      Freq.     Percent        Cum.
------------+-----------------------------------
       0000 |      9,995       99.95       99.95
       4513 |          3        0.03       99.98
       4516 |          1        0.01       99.99
       5631 |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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