What are the relative dangers of these things?
Hours of exposure per fatality:
Driving a car: 7,100,000 hours
Walking on stairs: 714,000 hours
Going to hospital: 60,000 hours
Smoking: 60,000 hours
Skydiving: 16,000 hours
* Driving based on the calculations in the link and 25mph speed. Walking on stairs as per link with 2.5mph speed. Skydiving based on these statistics and duration of 6 minutes. Let me know via comment or message if you these assumptions look to be in error.