Frequencies for first 10,000 rows of pain variable in nhamcsed1998 dataset :

 presenting |
   level of |
       pain |      Freq.     Percent        Cum.
------------+-----------------------------------
    Unknown |      4,118       41.18       41.18
       None |      1,753       17.53       58.71
       Mild |      1,889       18.89       77.60
   Moderate |      1,484       14.84       92.44
     Severe |        397        3.97       96.41
      Blank |        359        3.59      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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