Transport-related variables for obstetric cases transferred by helicopter ambulance.

Table 2: Transport-related variables for obstetric cases transferred by helicopter ambulance.

Season Spring Summer Autumn Winter	13 13 9 3
Regions Inter-provincial From the hamlet to the provincial center From the county to the city center From the district to the provincial center	1 2 34 1
Helicopter flight time	63 minutes (IQR 52.50-78.75)
Estimated highway transfer time	96 minutes (IQR 87.75-124.5)

^*Variables are given as median (interquartile range) or number of cases