Change growth rate

I dont know why a stack of 30-40 bombers/tanks can destroy a city for the whole game. Its needs 100 weeks to restore a city to their former glory because the growth rate is fix at 1%/turn.
In ww2, thousands of bombers decrease the population of many cities (e.g cologne )
but the inhabitants rebuilt the city in a fraction of the time

my suggestion:
population < 85% -> growth rate = 15%
population =>85% -> grwoth rate 1%

100 turns is more realistic right