When anything says past x years it's talking from some shifting point in the sand and can be assumed to be about 150 years ago.
When an author wants to specify a specific range in time they would state "From 1932-1958" instead of saying over the course of 26 years.
Regardless....whether its 2250, 2500, or 2600+ it doesn't significantly change anything for what I wrote probably right before I went to bed.
In exactly 150 years, assuming 150 initiations took place, 2250 members would have been admitted. Depending on what significant digits you want to round too (in typical texts 500's are a common one)...2500 is correct. It makes for easier reading and it's easier for most people to think of that quantity. Doing things like 2499 makes many people think a way lower quantity than what they would had 2500 been stated.
Again however, it's a matter of attacking the side issues than the issues itself. It never fails that someone says "oh oh oh you didn't spell [whatever issue] right, so they/it must have never existed!!!!!"