Frequencies for first 10,000 rows of int_pnspuna variable in mcbsatc2013 datase

      Proxy |
  necessary |
     due to |
unavailabil |
        ity |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        141        1.41        1.41
          2 |        958        9.58       10.99
          . |      8,901       89.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 24 May 2016