Frequencies for first 10,000 rows of hematocr variable in nhamcsopd2000 dataset :

hematocrit/ |
 hemoglobin |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,438       94.38       94.38
          1 |        562        5.62      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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