The Himalaya by the Numbers: A Statistical Analysis - Himalayan ...

In general, death rates for hired follow a similar pattern for members except for the
Kangchenjunga-Janak, Manaslu-Ganesh, and Kanjiroba-Far West regions where hired
death rates are substantially lower than member death rates.
Deaths by Climbing Season
Chart D-11 shows death rates for members and hired personnel by climbing season for
all peaks.
2.5
2.0
1.5
1.0
0.5
0.0
1.64
All Seasons
571/34920
1.70
Spring
270/15865
Death Rates by Seasons for All Peaks (1950-2006)
0.32
Summer
1/316
1.56
Autumn
270/17264
2.03
Winter
30/1475
Chart D-11: Member and hired death rates by climbing season for all peaks from 1950-2006
(the death rate is above the column bar; the death and above BC counts are below)
The columns outlined in black in the above chart represent seasons that statistically have
either significantly higher or lower death rates than the mean death rate for all seasons.
Statistical significance means that there is less than a 5% probability that the result
occurred by chance. For the non-outlined peaks, the death rates can be considered as only
anecdotal evidence of higher or lower death rates than the mean rate for all seasons.
The differences in member death rates between seasons are statistically insignificant,
even though the summer and winter seasons are considerably lower and higher,
respectively, than the mean death rate for all seasons.
The hired death rates for the autumn season of 1.88% and the spring season of 1.02%
statistically are significantly higher and lower, respectively, than the mean ascent rate
of 1.40% for all seasons. The hired winter death rate of 2.18% is nearly significant, but
the lower death and above base camp counts keep it from being as significant as the
spring and autumn seasons.
1.40
All Seasons
211/15031
Members Hired
1.02
Spring
86/8402
0.76
Summer
1/132
1.88
Autumn
109/5809
2.18
Winter
15/688
Death Analysis 93