Frequencies for rx_ce_lti_rxhcc68 variable in rxcoeff dataset :

Rx_CE_LTI_R |
  XHCC68 -- |
    Mild or |
Unspecified |
     Mental |
Retardation |
/Developmen |
 tal Disabi |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |          1      100.00      100.00
------------+-----------------------------------
      Total |          1      100.00

by Jean Roth , jroth@nber.org , 2 May 2016