Frequencies for first 10,000 rows of importdate variable in plan2014 dataset :

        Import Date |      Freq.     Percent        Cum.
--------------------+-----------------------------------
2013-06-04 08:25:28 |          6        0.06        0.06
2013-06-05 12:49:14 |          4        0.04        0.10
2013-06-06 10:50:48 |         25        0.25        0.35
2013-06-07 09:05:04 |         15        0.15        0.50
2013-06-28 08:36:25 |         17        0.17        0.67
2013-07-01 08:34:30 |         21        0.21        0.88
2013-07-01 22:22:31 |         20        0.20        1.08
2013-07-02 22:25:47 |          4        0.04        1.12
2013-07-23 22:50:01 |          4        0.04        1.16
2013-07-31 07:05:07 |          7        0.07        1.23
2013-08-01 12:48:00 |         11        0.11        1.34
2013-08-09 08:21:29 |          4        0.04        1.38
2013-08-14 11:02:32 |         14        0.14        1.52
2013-08-30 07:44:10 |        589        5.89        7.41
2013-09-02 11:39:25 |        344        3.44       10.85
2013-09-05 07:36:38 |         30        0.30       11.15
2013-09-10 14:43:20 |        180        1.80       12.95
2013-09-11 07:49:18 |         29        0.29       13.24
2013-09-12 11:27:35 |        116        1.16       14.40
2013-09-13 08:31:59 |         12        0.12       14.52
2013-09-16 06:33:22 |         12        0.12       14.64
2013-09-17 16:07:07 |        319        3.19       17.83
2013-09-19 06:29:55 |          8        0.08       17.91
2013-09-22 09:35:26 |          8        0.08       17.99
2013-09-25 08:49:23 |         64        0.64       18.63
2013-10-15 07:27:56 |        615        6.15       24.78
2013-10-16 16:52:58 |         16        0.16       24.94
2013-11-23 14:44:18 |        415        4.15       29.09
2013-11-25 12:40:15 |         28        0.28       29.37
2013-11-26 13:14:08 |        690        6.90       36.27
2013-12-20 07:30:10 |         65        0.65       36.92
2014-01-15 07:08:32 |        145        1.45       38.37
2014-01-16 07:24:04 |        501        5.01       43.38
2014-01-17 09:36:20 |      1,096       10.96       54.34
2014-01-21 08:29:49 |      2,061       20.61       74.95
2014-01-22 07:31:14 |         12        0.12       75.07
2014-01-29 08:00:05 |        519        5.19       80.26
2014-03-19 07:06:49 |      1,385       13.85       94.11
2014-04-18 11:49:29 |         78        0.78       94.89
2014-05-02 13:10:05 |        194        1.94       96.83
2014-07-25 16:54:18 |        317        3.17      100.00
--------------------+-----------------------------------
              Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 8 Dec 2017