Frequencies for first 10,000 rows of hematocr variable in namcs1999 dataset :

hematocrit/ |
 hemoglobin |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,599       95.99       95.99
          1 |        401        4.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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