Frequencies for first 10,000 rows of lpn variable in nhamcsed1999 dataset : licensed | practical | nurse seen | Freq. Percent Cum. ------------+----------------------------------- 0 | 9,669 96.69 96.69 1 | 331 3.31 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016