Frequencies for contractid variable in pdp2015 dataset :

Contract ID |      Freq.     Percent        Cum.
------------+-----------------------------------
            |          1        0.07        0.07
      S0522 |         86        5.92        5.99
      S0962 |          1        0.07        6.06
      S1030 |          4        0.28        6.34
      S1140 |          2        0.14        6.47
      S2468 |          2        0.14        6.61
      S2505 |          7        0.48        7.09
      S2874 |          2        0.14        7.23
      S2893 |          8        0.55        7.78
      S3440 |          1        0.07        7.85
      S4054 |          2        0.14        7.99
      S4219 |          1        0.07        8.06
      S4802 |          7        0.48        8.54
      S5540 |          2        0.14        8.68
      S5552 |          3        0.21        8.88
      S5569 |          2        0.14        9.02
      S5580 |          3        0.21        9.23
      S5584 |          2        0.14        9.37
      S5593 |          4        0.28        9.64
      S5596 |         36        2.48       12.12
      S5601 |        101        6.96       19.08
      S5609 |          4        0.28       19.35
      S5617 |        153       10.54       29.89
      S5660 |        102        7.02       36.91
      S5715 |         12        0.83       37.74
      S5726 |          3        0.21       37.95
      S5743 |         21        1.45       39.39
      S5753 |          2        0.14       39.53
      S5755 |        137        9.44       48.97
      S5768 |        100        6.89       55.85
      S5795 |          2        0.14       55.99
      S5805 |          1        0.07       56.06
      S5810 |         99        6.82       62.88
      S5820 |         55        3.79       66.67
      S5877 |          4        0.28       66.94
      S5884 |        150       10.33       77.27
      S5904 |          2        0.14       77.41
      S5916 |          4        0.28       77.69
      S5921 |         51        3.51       81.20
      S5953 |          2        0.14       81.34
      S5967 |        100        6.89       88.22
      S5983 |          2        0.14       88.36
      S5993 |          2        0.14       88.50
      S6506 |          2        0.14       88.64
      S7230 |          4        0.28       88.91
      S7610 |          1        0.07       88.98
      S7694 |         60        4.13       93.11
      S9579 |        100        6.89      100.00
------------+-----------------------------------
      Total |      1,452      100.00

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