In my city (Hamilton, Ontario, Canada), there is a 20+ difference in life expectancy between the most affluent and most impoverished neighbourhoods. Even within countries, averages mask deep inequalities.

My city Vancouver, has the average life expectancy in Canada - but this is due to the population mix (lots of Japanese centenarians) not due to the medical benefits of rain.

Life expectancy varies with age [e(x), with x = current age]. The key question is, how long can someone who is your age now expect to live? In other words, in some places may be hard to make it to, say, 40 years old, but if you do you may have a better chance of making it to 75. I don't know about Bulgaria particularly, however.

I was born a little while north of you. What I would tell most guys born in that general region is: "quit smoking, drink less, and watch your diet". That should raise their life expectancy by a decade, I guess.

Probably will change by the time you're that old, I'm expecting.