Frequencies for po_box variable in ime_gme2552_96_2011 dataset :

                                 PO BOX |      Freq.     Percent        Cum.
----------------------------------------+-----------------------------------
                                        |         27       79.41       79.41
                                     .. |          3        8.82       88.24
1269                                 .. |          1        2.94       91.18
186                                  .. |          1        2.94       94.12
240                                  .. |          1        2.94       97.06
392                                  .. |          1        2.94      100.00
----------------------------------------+-----------------------------------
                                  Total |         34      100.00

by Jean Roth , jroth@nber.org , 21 Apr 2018