MT includes 18 basic ("by term") careers and 4 advanced ("by year") careers. The 18 basic careers are 5 of the 6 from Book 1 (no Other), all 12 from Supplement 4, and the Law Enforcer (which I believe premiered in issue #4 of The Travellers' Digest -- it's not the same as the Law Enforcer career that was in one of the early issues of Challenge)*. The 4 advanced careers were the char-gen sections of Books 4-7. C.O.A.C.C. (an MT supplement) also presented an advanced career sequence for Flyer characters, and DGP's The Early Adventures included a basic-career for Journalists (based on their CT journalist career from TD#2, and once again not the same as the Journalist career presented around the same time in Challenge). The two DGP alien books included race-specific basic (but not advanced)char-gen tables for the appropriate races (i.e. Vilani, Vargr, Solomani, Aslan).
Hope this helped.
*Note: basic char-gen in MT is slightly different than CT Book 1 & supp. 4 in that there's an extra roll for Special Duty, success at which gives the character an extra skill for the term, and a sub-rule that states that any roll (commission, promotion, special duty) that succeeds by 4+ (i.e. roll 11+ on an 7+ roll) provides 2 extra skills instead of one. These changes were made to bring basic characters' skill-totals more in line with those generated under the advanced systems. Also the skill charts have been modified with many more Cascade and Cluster skills (where the player is allowed to choose one of several skills from a list). This allowed all character-types a broader mix of available skills and gave the player a bit more choice in what his character would eventually look like. IMO char-gen is one of MT's unambiguous improvements over CT -- it includes everything that was good about CT char-gen, plus a little bit more.
