Correct Drawdown % Calculation

Hi,

Using Open API v1 to place and close trades by "mirroring" another account trades.

Can anyone explain how I can calulate the correct drawdown for each account in realtime? From what I have read, the drawdown is calcuated by looking at the account balance and see how far the equity on that account has gone below. e.g. Account Balance was 10,000 and the equity is at 9,000 so it has lost 1,000 or 10%.

If this is correct, is the Account Balance taken at the point the trade was put on? Using the example above, 10,000 balance and equity is 9,000 but durring the time the trade was in place I deposit another 10,000 into the account then the balance is now 20,000. So if I work out the drawdown based on this 20,000 is this right? or do I still work out the drawdown based on the Account Balance when the trade was placed i.e 10,000.

Either way, is this possible using Open API v1? I can get the Account Balance when a trade is closed using the ClosedPositionDetails class but I don't see how I can obtain the Account Balance at the precise moment the trade is placed.

Thanks in advance