Therefore, it is difficult to say the exact figure.
"Urban" constantly inhale harmful vapors, feed on leftovers in landfills. Of course, this does not make the bird healthier in any way. Therefore, they often die early, having lived only 10 years.
So, if this is not an industrial area, then the air is much cleaner, therefore, the conditions are different. This affects life expectancy because they can even "celebrate" their 30th birthday.
They live in nature for about 15 years, but some individuals live up to 40. There is fresh air here, but the danger comes from predators. Mortality increases in frosty winters and lean years. Whole flocks perish during this period.