Frequencies for first 10,000 rows of psych_unit_trmnn_dt variable in pos2011 dataset :

psych_unit_ |
   trmnn_dt |      Freq.     Percent        Cum.
------------+-----------------------------------
          . |     10,000      100.00      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 20 Apr 2019