Frequencies for first 10,000 rows of uca_muscu variable in natl2004 dataset :

      Other |
Musculoskel |
       etal |
Anomalies U |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |          8        0.08        0.08
          2 |      8,766       87.66       87.74
          9 |      1,226       12.26      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 21 Jan 2016