Frequencies for first 10,000 rows of hematocr variable in namcs1997 dataset :

hematocrit/ |
 hemoglobin |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,484       94.84       94.84
          1 |        516        5.16      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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