Frequencies for first 10,000 rows of therpr22 variable in namcs2000 dataset :

      other |
  ther/prev |
 service #2 |
    - 2 dgt |      Freq.     Percent        Cum.
------------+-----------------------------------
         00 |      9,994       99.94       99.94
         48 |          1        0.01       99.95
         93 |          2        0.02       99.97
         94 |          3        0.03      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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