87/tic with 378 PIE (in party), max MP was 4391. Rate: 1.981% MP/tic
72/tic with 279 PIE (in party), max MP was 3642. Rate: 1.976% MP/tic

Tested as male Wildwood Elezen SHC. In-combat with both, of course. So over the course of a little over 2m30s, you will have naturally regen'd your whole MP.

Incidentally, in-combat TP regen is 60/tic.