Frequencies for contractid variable in pdp2011 dataset :

Contract ID |      Freq.     Percent        Cum.
------------+-----------------------------------
      S0043 |          3        0.21        0.21
      S0197 |          1        0.07        0.28
      S0655 |          8        0.55        0.83
      S1030 |          4        0.28        1.10
      S1131 |          2        0.14        1.24
      S2321 |          2        0.14        1.38
      S2468 |          1        0.07        1.45
      S2505 |          5        0.34        1.79
      S2770 |          2        0.14        1.93
      S2874 |          2        0.14        2.07
      S2893 |          8        0.55        2.62
      S3389 |          2        0.14        2.76
      S3440 |          1        0.07        2.83
      S3521 |          2        0.14        2.97
      S4219 |          2        0.14        3.10
      S4802 |         50        3.45        6.55
      S5540 |          2        0.14        6.69
      S5552 |          3        0.21        6.90
      S5555 |          2        0.14        7.03
      S5569 |          1        0.07        7.10
      S5580 |          1        0.07        7.17
      S5584 |          2        0.14        7.31
      S5585 |          1        0.07        7.38
      S5593 |          4        0.28        7.66
      S5596 |         36        2.48       10.14
      S5601 |        102        7.03       17.17
      S5609 |          4        0.28       17.45
      S5617 |        102        7.03       24.48
      S5644 |         51        3.52       28.00
      S5660 |        102        7.03       35.03
      S5670 |         25        1.72       36.76
      S5674 |         25        1.72       38.48
      S5715 |          8        0.55       39.03
      S5726 |          3        0.21       39.24
      S5743 |         14        0.97       40.21
      S5753 |          2        0.14       40.34
      S5755 |         50        3.45       43.79
      S5766 |          6        0.41       44.21
      S5768 |         50        3.45       47.66
      S5775 |          2        0.14       47.79
      S5795 |          2        0.14       47.93
      S5803 |        102        7.03       54.97
      S5805 |          1        0.07       55.03
      S5820 |         60        4.14       59.17
      S5825 |          2        0.14       59.31
      S5840 |          2        0.14       59.45
      S5857 |          1        0.07       59.52
      S5877 |          4        0.28       59.79
      S5884 |        142        9.79       69.59
      S5904 |          2        0.14       69.72
      S5907 |          2        0.14       69.86
      S5916 |          4        0.28       70.14
      S5921 |         51        3.52       73.66
      S5932 |         51        3.52       77.17
      S5937 |          1        0.07       77.24
      S5953 |          2        0.14       77.38
      S5960 |         73        5.03       82.41
      S5966 |          1        0.07       82.48
      S5967 |        100        6.90       89.38
      S5983 |          2        0.14       89.52
      S5993 |          2        0.14       89.66
      S5998 |         44        3.03       92.69
      S7694 |        102        7.03       99.72
      S8067 |          4        0.28      100.00
------------+-----------------------------------
      Total |      1,450      100.00

by Jean Roth , jroth@nber.org , 14 Apr 2016