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

 how many past |
visits in last |
    12 months? |      Freq.     Percent        Cum.
---------------+-----------------------------------
         Blank |        396        3.96        3.96
          None |        291        2.91        6.87
           1-2 |      2,202       22.02       28.89
           3-5 |      2,225       22.25       51.14
     6 or more |      2,640       26.40       77.54
       Unknown |        774        7.74       85.28
Not applicable |      1,472       14.72      100.00
---------------+-----------------------------------
         Total |     10,000      100.00

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