It claims to cite statistics from 2007 - 2012.
But can it be accurate considering bigger promotions didn't have featherweight / bantamweight / flyweight divisions until recently?
There wasn't the type of support nor interest in lighter weight classes to allow fighters in them to develop as much as fighters in other weight classes in a generalized sense?
To make an accurate comparison there will need to be more fighters & the lighter divisions will need to be as stacked & deep as the heavier divisions where there are tons of good fighters?
Its not a good comparison as the lighter divisions are newer & not as developed?