if ranks were based on size of sorority

Generally the larger chapters have the best retention rate obviously.

It just shows which houses had more girls graduating also

Houses that have lower retention rates doesn't necessary equate with girls not liking their house. This has already been said before, but OR houses tend to have better retention rates because their girls knew what they were getting into... Most of the time, they've had mothers or grandmothers who went Greek and thus their family is more understanding and willing to cover the (high) expenses. Many of these girls also see sorority life as more than just sisterhood. They see it as a form of social status, not just on campus but also back home. OR girls are also generally from the state of Alabama or surrounding Southern states... This means, these girls aren't the type to transfer to a school closer to home because they miss their family or whatever.

NR houses face the biggest drop rates because of things such as girls who transfer out of school, girls who can't pay for sorority life, girls who have made friends but then decide it's not worth the thousands of dollars because they can see each other whenever, etc.

I mean, are there girls who drop houses because they just don't like them? Yes, but that occurs in EVERY house, both OR and NR. More often than not, girls tend to drop their sororities because of fundamental issues such as grades, money, friends, transfers rather than just because they didn't like the house itself.

OR it could mean the houses with less members just had bigger graduating classes?

All of what @no said is true. The other huge thing about old row houses is that it's a status symbol-- if a girl in a lower house with no motive doesn't like her house she will drop, but a girl in say XO or KD is less likely to drop even if she hates it because of the status it affords on campus and probably in her hometown.

Exactly... There are different reasons why a chapter doesn't have as high amount of active members as other houses. Sometimes people graduate early, sometimes people transfer out, sometimes people can't keep up with the financial burden of Greek life, etc. There are definitely girls in ALL houses who drop because they dislike their sorority... But like the person above said, it's mainly other "fundamental" reasons as to why girls drop.

Yes it is, #13

Always someone to make a bigger issue out of something small. Stop trying to perpetuate stereotypes and hate and go do something better with your time. If houses doing COB were truly having a difficult time with retention then their chapter would be pulled. And as I see it right now, all houses are doing extremely well.

you do know girls also graduate in December right lol

I'd also like to mention that a lot of top houses at FSU do Spring COB... Obviously FSU and Bama's Greek systems aren't identical but they're comparable in size and competitiveness. That being said, a chapter will do what's best for them. If they see that a large group of girls graduated early in December or if they see a few girls transferred out (or whatever else) then they're going to be proactive about filling in those gaps. And in all honesty, houses who don't do Spring COB even though they had a high amount of girls drop for whatever reason are only hurting themselves. Houses who COB aren't "bad" houses, they're just being proactive about a dip in total members.