Frequencies for first 10,000 rows of ewarnr variable in namcs2014 dataset :

 If orders for prescriptions |
   submitted electronically, |
  warnings of drug interacti |      Freq.     Percent        Cum.
-----------------------------+-----------------------------------
                     Unknown |        258        2.58        2.58
              Not applicable |      1,829       18.29       20.87
                         Yes |      7,553       75.53       96.40
                          No |        360        3.60      100.00
-----------------------------+-----------------------------------
                       Total |     10,000      100.00

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