Frequencies for first 10,000 rows of wlkdif13 variable in h84 dataset :

 DIFFICULTY |
  WALKING 3 |
     BLOCKS |      Freq.     Percent        Cum.
------------+-----------------------------------
         -8 |          4        0.04        0.04
         -1 |      8,973       89.73       89.77
          1 |        220        2.20       91.97
          2 |        284        2.84       94.81
          3 |        236        2.36       97.17
          4 |        283        2.83      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 28 Feb 2018