Frequencies for first 10,000 rows of arrive variable in nhamcsed1998 dataset :

                        mode of arrival |      Freq.     Percent        Cum.
----------------------------------------+-----------------------------------
                 Ambulance (air/ground) |      1,676       16.76       16.76
Public Service (nonambulance, e.g polic |        340        3.40       20.16
                                Walk-in |      7,356       73.56       93.72
                                Unknown |        380        3.80       97.52
                                  Blank |        248        2.48      100.00
----------------------------------------+-----------------------------------
                                  Total |     10,000      100.00

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