Frequencies for first 10,000 rows of arrive variable in nhamcsed2000 dataset :

                        mode of arrival |      Freq.     Percent        Cum.
----------------------------------------+-----------------------------------
                 Ambulance (air/ground) |      1,593       15.93       15.93
Public Service (nonambulance, e.g polic |        299        2.99       18.92
                                Walk-in |      7,360       73.60       92.52
                                Unknown |        486        4.86       97.38
                                  Blank |        262        2.62      100.00
----------------------------------------+-----------------------------------
                                  Total |     10,000      100.00

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