Frequencies for first 10,000 rows of uld_anest variable in natl2004 dataset :

 Anesthetic |
Complicatio |
       ns U |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |          2        0.02        0.02
          2 |      9,024       90.24       90.26
          9 |        974        9.74      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 21 Jan 2016