Frequencies for first 10,000 rows of icu_srvc_cd variable in pos2009 dataset :

 SRV: ICU - |
MEDICAL/SUR |
      GICAL |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      8,638       86.38       86.38
          0 |        540        5.40       91.78
          1 |        777        7.77       99.55
          2 |         31        0.31       99.86
          3 |         14        0.14      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 17 May 2017