Frequencies for b_1_c18_31 variable in snf_rollup2540_96_2011 dataset :

 b_1_c18_31 |      Freq.     Percent        Cum.
------------+-----------------------------------
        149 |          1        0.06        0.06
        660 |          1        0.06        0.11
       2690 |          1        0.06        0.17
       2812 |          1        0.06        0.22
       8622 |          1        0.06        0.28
      10685 |          1        0.06        0.33
      21140 |          1        0.06        0.39
          . |      1,802       99.61      100.00
------------+-----------------------------------
      Total |      1,809      100.00

by Jean Roth , jroth@nber.org , 17 Feb 2018