MGM Rewards Mastercard Offer History?

Does anyone know if there's any info floating around that tracks past welcome bonus offers for the MGM Mastercard? Wanting to sign up in advance of a bunch of trips to Vegas this summer, but read on a post from last summer that there was a welcome offer of 20,000 at some point, so I'm wondering if I should hold off at least a few months to see if anything comes back around that time of year recurringly.