difference - " Have to " vs "Have had to "

1) This is not the first time that the residents of the capital have had to suffer such inconveniences. (This is collected from a daily newspaper)

2) "This is not the first time that the residents of the capital have to suffer such inconveniences.

I know the rules of "have to/has to, had to ". But I haven't found anything on "have/has had to ".

Would somebody tell me the difference between those sentences?