Time Gated Plagues
Sets the 4 main plagues to a minimum time in-between of 75% of their respective maximum duration time.
Example:
Merturov Plague Maximum Duration = 3 years
Minimum Interval In Between Plague Per Empire = 3/100*75 = 2.25 years
Still can go on forever but once the cures have been researched and they can be cured withing a short time they wont immediately start again.
Need observe prevalence of Plagues in general now and maybe fine tune the value.
