07: Chiapas
Sequencing note: Just in case your knowledge of the Spanish alphabet is as, uh, lacking as mine was, "Chiapas" and "Chihuahua" were assigned alphabetical codes 07 and 08 respectively, behind Coahuila and Colima, because "Ch" was its own letter in the Spanish alphabet, coming between C and D, until officially eliminated in 2000. The Mexican federal government assigned the serial blocks according to where the names fall within the new, Ch-less alphabet, though, with Chihuahua given plates in the late Dxx series while Coahuila has them in the late Exx series. Odd.