Frequencies for first 10,000 rows of srotaton variable in sippp08putm1 dataset :

        SU: |
Rotation of |
       data |
 collection |      Freq.     Percent        Cum.
------------+-----------------------------------
          2 |      2,961       29.61       29.61
          3 |      5,207       52.07       81.68
          4 |      1,832       18.32      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 3 Jan 2016