Frequencies for first 10,000 rows of prov1325 variable in pos1993 dataset : tech super | - histo | pathology | Freq. Percent Cum. ------------+----------------------------------- 0 | 9,973 99.73 99.73 1 | 23 0.23 99.96 2 | 2 0.02 99.98 3 | 1 0.01 99.99 5 | 1 0.01 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 26 Jan 2016