Why the difference in death rates from covid 19

[hutch622]

I was looking through the stats for cv19 and for the life of me i cant work out why the discrepancy in death rates around the world , especially amongst the 5 eyes nations . First up the world average sits at 3.76% which is a vast improvement over earlier day . 
now for 5 eye nations .
Australia = 1.28%
Canada = 7.57%
New Zealand = 1.4%
United Kingdom = 15.04%
United States = 3.27% 
I would have thought our hospital systems to be roughly on par , certainly our medium ages are sort of close going from 38-42 . Life expectancy was between 79 and 83 years old so overall no huge discrepancies . Reporting criteria maybe ? . Scratching my head here a little , any ideas .
Thoughts RN3 .
source for cv
Life expectancy
Medium age