Frequencies for first 10,000 rows of ldl variable in nhamcsopd2011 dataset :

 Was low density lipoprotein (LDL) |
    drawn within 12 months of this |
                            visit? |      Freq.     Percent        Cum.
-----------------------------------+-----------------------------------
                             Blank |      2,305       23.05       23.05
Not applicable, provider not asked |        218        2.18       25.23
                               Yes |      1,825       18.25       43.48
       None found within 12 months |      5,652       56.52      100.00
-----------------------------------+-----------------------------------
                             Total |     10,000      100.00

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