Somebody must've beat this game. Please give us some tips! :) I'm stuck in December Year 3, and can't figure out what upgrade I need in order to get 2100 points. Thanks!

Just finished the game - the upgrade I had were everything except - one oven was not completely maxed out and one decorating tray was not maxed out.  Otherwise I had everything else. 
 
I'm frustrated that my disk says Cake Mania Deluxe and the box says 84 levels yet when the game loads I have 36 levels and it says its "Back to the Bakery"  Jill stays in the same location. 
 
I just beat December year 3 and then it says " The End"   I thought there would be more

Thank you Lynne! I'll try replaying Year 3 again because two of the ovens weren't completely upgraded when I played before. I'm going to try it like you did. It's good to know that's the last level, I've been trying to beat this for weeks! Thanks again! :)