Frequencies for first 10,000 rows of genital variable in linkco1991us_num dataset : Malformed | genitalia | Freq. Percent Cum. ------------+----------------------------------- 1 | 61 0.61 0.61 2 | 9,666 96.66 97.27 9 | 273 2.73 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 22 Dec 2015