axis and allies 1942 board game?

[magicbeatledel]

Hi,
Anyone play axis and allies? I have just bought the standard 1942 edition. however i am confused already. On page 6 of the rulebook, it tells you to place a control marker on the national production chart on the board that matches your powers starting ipc total and then keep track of it. Ok, i get that. However, on the next page it tells you to elect one player as banker who then keeps track of each powers ipc total on a peice of paper. My question is: Why do you need a piece of paper to track your ipc's if you have a chart on the board to do it? Am I missing something? Any help would be most appreciated.
Thanks