Frequencies for first 10,000 rows of arrive variable in nhamcsed1997 dataset :

                        mode of arrival |      Freq.     Percent        Cum.
----------------------------------------+-----------------------------------
                 Ambulance (air/ground) |      1,640       16.40       16.40
Public Service (nonambulance, e.g polic |        341        3.41       19.81
                                Walk-in |      7,520       75.20       95.01
                                Unknown |        358        3.58       98.59
                                  Blank |        141        1.41      100.00
----------------------------------------+-----------------------------------
                                  Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 28 Mar 2016