Frequencies for first 10,000 rows of pastvis variable in nhamcsopd2004 dataset :

 how many past |
visits in last |
    12 months? |      Freq.     Percent        Cum.
---------------+-----------------------------------
          none |        517        5.17        5.17
           1-2 |      2,524       25.24       30.41
           3-5 |      2,460       24.60       55.01
     6 or more |      2,708       27.08       82.09
not applicable |      1,791       17.91      100.00
---------------+-----------------------------------
         Total |     10,000      100.00

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