Frequencies for first 10,000 rows of month variable in nadac dataset :

As of Month |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      1,011       10.11       10.11
          2 |        890        8.90       19.01
          3 |        820        8.20       27.21
          4 |        839        8.39       35.60
          5 |        765        7.65       43.25
          6 |        762        7.62       50.87
          7 |        808        8.08       58.95
          8 |        778        7.78       66.73
          9 |        743        7.43       74.16
         10 |        748        7.48       81.64
         11 |        822        8.22       89.86
         12 |      1,014       10.14      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 1 Mar 2018