Frequencies for first 10,000 rows of ectoee variable in nhamcsed2009 dataset :

    does ed |
       have |
computerize |
   d system |
 for orders |
 for tests? |      Freq.     Percent        Cum.
------------+-----------------------------------
         -8 |         81        0.81        0.81
          1 |      8,736       87.36       88.17
          2 |      1,057       10.57       98.74
          4 |        126        1.26      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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