Frequencies for first 10,000 rows of pain variable in nhamcsed2008 dataset :

 presenting |
   level of |
       pain |      Freq.     Percent        Cum.
------------+-----------------------------------
      blank |        351        3.51        3.51
    unknown |      1,760       17.60       21.11
       none |      1,976       19.76       40.87
       mild |      1,375       13.75       54.62
   moderate |      2,161       21.61       76.23
     severe |      2,377       23.77      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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