
average lifespan of a junior coach
A similar study was undertaken in another sport by the governing organisation. The distribution was found to be very skewed. When looking at the data, the "average" can be expressed as either:
Mean: The sum of all the data / the number of events
Median: The 50% percentile
Mode: The most common
They found that the Mode was around 4 years experience, the median was around 6 years and the mean was over 10 years due to the skew and a couple of coaches who had been coaching for over 30 years.
I think you'll find a similar result in basketball. There's a few coaches who have been coaching for years and who are now coaching the kids of the kids they first coached. There would be a group of coaches who see coaching as their outlet and just love it. Then there would be a group, eg young players, who get involved while they are at Uni, then once they start working put their focus into their work, then come back at a later date.
Like all volunteers, I expect that they don't stop because they hate what they do, they just need a break every so often!

To measure an average lifespan, you would have to also take in to account the lifestyle one leads ie ; smoker, drinker etc.
I wouldn't think being a coach would take years off your life though. Unlike your own kids, you send these home after a couple of hours.
Also depends on the country you live in.
http://en.wikipedia.org/wiki/List_of_countries_by_life_expectancy

Dennis Jones at West Adelaide would have been coaching Junior Boys for 25+ years

