Frequencies for first 10,000 rows of a1c variable in namcs2010 dataset :

    was glycohemoglobin |
  (hgba1c) drawn within |
              12 months |      Freq.     Percent        Cum.
------------------------+-----------------------------------
                  blank |     10,000      100.00      100.00
------------------------+-----------------------------------
                  Total |     10,000      100.00

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