Frequencies for first 10,000 rows of asth_sev variable in namcs2012 dataset :

    Asthma severity |      Freq.     Percent        Cum.
--------------------+-----------------------------------
              Blank |         59        0.59        0.59
     Not applicable |      9,363       93.63       94.22
       Intermittent |         99        0.99       95.21
    Mild persistent |         49        0.49       95.70
Moderate persistent |         32        0.32       96.02
  Severe persistent |         17        0.17       96.19
    Other - Specify |         23        0.23       96.42
      None recorded |        358        3.58      100.00
--------------------+-----------------------------------
              Total |     10,000      100.00

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