Frequencies for first 10,000 rows of hlt_difwrite variable in mcbsatc2013 datas

     Lvl of |
 difficulty |
write/handl |
   e object |      Freq.     Percent        Cum.
------------+-----------------------------------
         -8 |          8        0.08        0.08
         -7 |          2        0.02        0.10
          1 |      6,961       69.61       69.71
          2 |      1,276       12.76       82.47
          3 |      1,044       10.44       92.91
          4 |        574        5.74       98.65
          5 |        135        1.35      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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