Frequencies for first 10,000 rows of avdirsu variable in nsrd dataset :

Average Direct |
        Normal |
   Uncertainty |
          Flag |      Freq.     Percent        Cum.
---------------+-----------------------------------
Not Applicable |         40        0.40        0.40
        13-18% |        996        9.96       10.36
        18-25% |      1,332       13.32       23.68
        25-35% |      7,397       73.97       97.65
        35-50% |        235        2.35      100.00
---------------+-----------------------------------
         Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 15 Jun 2016