Frequencies for first 10,000 rows of pain variable in nhamcsed1999 dataset :

 presenting |
   level of |
       pain |      Freq.     Percent        Cum.
------------+-----------------------------------
    Unknown |      5,221       52.21       52.21
       None |      1,163       11.63       63.84
       Mild |      1,674       16.74       80.58
   Moderate |      1,173       11.73       92.31
     Severe |        400        4.00       96.31
      Blank |        369        3.69      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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