Frequencies for first 10,000 rows of bcbs variable in nhamcsopd1995 dataset :

       blue |
 cross/blue |
     shield |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,104       91.04       91.04
          1 |        896        8.96      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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