Frequencies for first 10,000 rows of exmwi22d variable in nhamcsopd2001 dataset :

       exam |
write-in #2 |
  - 2 digit |      Freq.     Percent        Cum.
------------+-----------------------------------
         00 |      9,124       91.24       91.24
         89 |        664        6.64       97.88
         91 |          1        0.01       97.89
         94 |         45        0.45       98.34
         95 |        165        1.65       99.99
         99 |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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