I doubt any trends you might find would be reliable after a month. An MSC might have a severe shortage of shoppers in an area until a project ends. Then you wouldn’t be able to find anything there for six months.
Other places they may struggle to find shoppers simply because the fees are too low. Probably not worth traveling.
Then again, areas that seem to have an over abundance of shoppers can change overnight when a high-volume shopper quits or moves. In those cases, MSC’s might be begging and bonusing like crazy to make up the 100+ shops that one person had been doing each month.
There are also times when MSC’s have an area where they historically can’t find shoppers and they’ll offer travel and hotel reimbursement to a specific shopper or two to do a long route, and those will never make it to a job board.
Anyways, it changes so much and so rapidly that any data would be of historical value only.