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

  in last 2 |
 years, has |
       ed's |
   physical |
 space been |
  expanded? |      Freq.     Percent        Cum.
------------+-----------------------------------
         -9 |         42        0.42        0.42
         -8 |        521        5.21        5.63
          1 |      2,685       26.85       32.48
          2 |      6,752       67.52      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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