Frequencies for first 10,000 rows of scpwi23d variable in namcs2001 dataset :

      scope |
  procedure |
write-in #2 |
  - 3 digit |      Freq.     Percent        Cum.
------------+-----------------------------------
        000 |      9,975       99.75       99.75
        451 |          8        0.08       99.83
        452 |         15        0.15       99.98
        563 |          1        0.01       99.99
        573 |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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