Changing number of randomly generated towns in scenario editor

[lange]

Hello,

I am currently trying to create a scenario in the scenario editor on a 4096*2048-sized map and would like to include around 750-800 towns in it. The main problem for me is that the function "Many random towns" generates too many new towns, in my case always more than 1300. I tried changing the number of towns in the new game settings both to low and custom with 750 towns, but the town generator still generates far more than 1000 towns.
Does anybody know how i can change the settings for the town generation in the scenario editor?
Thanks in Advance.