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

has patient been seen in |
     this clinic before? |      Freq.     Percent        Cum.
-------------------------+-----------------------------------
                   Blank |        219        2.19        2.19
Yes, established patient |      8,309       83.09       85.28
         No, new patient |      1,472       14.72      100.00
-------------------------+-----------------------------------
                   Total |     10,000      100.00

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