Frequencies for first 10,000 rows of ewarnr variable in namcs2013 dataset :

 If orders for prescriptions |
   submitted electronically, |
  warnings of drug interacti |      Freq.     Percent        Cum.
-----------------------------+-----------------------------------
                     Unknown |        229        2.29        2.29
              Not applicable |      2,020       20.20       22.49
                         Yes |      7,221       72.21       94.70
                          No |        490        4.90       99.60
Yes, but turned off/not used |         40        0.40      100.00
-----------------------------+-----------------------------------
                       Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 27 Mar 2017