Frequencies for first 10,000 rows of othultra variable in namcs2011 dataset :

      Other |
 ultrasound |      Freq.     Percent        Cum.
------------+-----------------------------------
         No |      9,808       98.08       98.08
        Yes |        192        1.92      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 28 Mar 2016