Frequencies for first 10,000 rows of mdcl_scl_workr_vlntr_cnt variable in pos2005 dataset : medical | social | workers - | volunteer | Freq. Percent Cum. ------------+----------------------------------- 0 | 9,975 99.75 99.75 .25 | 6 0.06 99.81 .5 | 2 0.02 99.83 1 | 15 0.15 99.98 2 | 1 0.01 99.99 3 | 1 0.01 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 17 May 2017