Frequencies for first 10,000 rows of prov2210 variable in pos1996 dataset :

       srv: |
 laboratory |
 (clinical) |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      8,803       88.03       88.03
          0 |         10        0.10       88.13
          1 |        875        8.75       96.88
          2 |        238        2.38       99.26
          3 |         74        0.74      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 26 Jan 2016