Frequencies for first 10,000 rows of eremind variable in namcs2009 dataset :

  practice has |
  comp sys for |
    remind for |
interven/scree |
   ning tests? |      Freq.     Percent        Cum.
---------------+-----------------------------------
         blank |         37        0.37        0.37
       unknown |        318        3.18        3.55
           yes |      4,280       42.80       46.35
            no |      5,238       52.38       98.73
    turned off |        127        1.27      100.00
---------------+-----------------------------------
         Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 28 Mar 2016