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

        was low density |
lipoprotein (ldl) 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