In Dallas......
I live in an area where there are a significant number of young (under 30) Asian and Mexican women that haven't had kids and regularly visit the gym (close to SMU).
Personal observation?
Mexican women CAN have booty. I've seen quite a few. The key is to find the ones that hit the gym and lift weights. Seen Mexican broads doing powercleans, squats, deadlifts, lunges etc. When they put their mind to it, they got azz genetics to tap into. Remember that most Mexicans have a little African DNA (less than 5% usually). They don't roll out of bed with booty but they can develop it.
Usually Mexicans have long booty so they need weights to develop the volume and projection.
Asian broads? I've seen countless Asian broads with flat stomachs, some even had nice plump titties, great legs....but still no booty. They get a nice shape with exercise but the projection isn't there. Indian women can have some thick booty but they are BY FAR the laziest women in the gym. All they do is walk on the treadmill at 2 mph and lift 5 lb weights for curls.