Frequencies for first 10,000 rows of ldl variable in namcs2011 dataset :

 Was low density lipoprotein (LDL) |
  drawn within 12 months of visit? |      Freq.     Percent        Cum.
-----------------------------------+-----------------------------------
                             Blank |      1,597       15.97       15.97
Not applicable, provider not asked |        933        9.33       25.30
                               Yes |      2,076       20.76       46.06
       None found within 12 months |      5,394       53.94      100.00
-----------------------------------+-----------------------------------
                             Total |     10,000      100.00

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