Frequencies for first 10,000 rows of ivfluids variable in nhamcsed1999 dataset :

  iv fluids |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      8,139       81.39       81.39
          1 |      1,861       18.61      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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