Frequencies for first 10,000 rows of prescr7 variable in namcs2008 dataset :

              prescription status code |      Freq.     Percent        Cum.
---------------------------------------+-----------------------------------
                     prescription drug |        813        8.13        8.13
                  nonprescription drug |         46        0.46        8.59
                          undetermined |         39        0.39        8.98
both prescription and over-the-counter |        199        1.99       10.97
                                     . |      8,903       89.03      100.00
---------------------------------------+-----------------------------------
                                 Total |     10,000      100.00

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