Frequencies for first 10,000 rows of f_uca_circul variable in natl2004 dataset : Other | Circulatory | /Respirator | y Anomalies | U | Freq. Percent Cum. ------------+----------------------------------- 0 | 8 0.08 0.08 1 | 9,992 99.92 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 21 Jan 2016