How many electronics does a person use and own in a lifetime?

Too vague to answer I believe. Can you narrow it down a little?

Considering that technology is ever advancing, people are keeping up with trends, therefore replacing their old electronics with new ones. Therefore, I would like to know on average, how many electronics does one buys/own in one's lifetime.

Are you referring specifically to Americans or Cubans or the entire planet? Is a radio considered 'electronics'? Are electronics toys and games included in this?
It's much too vague to answer.

Try here:
National Recycling Coalition--Electronics Recycling Initative

ELECTRONIC WASTE: A THREAT IN THE FUTURE

The entire planet. The average human being.
Lets just focus on computers alone.
Considering that computers only live up to 2 years instead of 6 back in 1997.