Frequencies for first 10,000 rows of alcohol variable in nhamcsed2003 dataset :

     is visit related to alcohol use? |      Freq.     Percent        Cum.
--------------------------------------+-----------------------------------
                                blank |        146        1.46        1.46
                   yes, patient's use |        260        2.60        4.06
              yes, other person's use |         16        0.16        4.22
                                   no |      8,468       84.68       88.90
                              unknown |      1,105       11.05       99.95
both patient's and other person's use |          5        0.05      100.00
--------------------------------------+-----------------------------------
                                Total |     10,000      100.00

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