Hi Tupp
The new API, and how welldonesoft have used it, allows us to address different football markets quite easily now. It's detailed in the manual around page 125, but each football market has a unique identifier now, so as an example you can address only the over under / under 2.5 goals using football8, so football8_market_volume will give you the market volume in that market. This calculated figure can be addressed by any related football market, so you could refer to market volume of the over under 2.5 goals market in the correct score market for that game.
You can also use these betting codes in the conditions of the trigger, so the condition would read markets betting code is xxxxx
Your trigger could be made using match_minute, which gives you the time passed in each game, excluding half-time so it's more useful than minutes since the off. Combine that with market_score1+market_score2 which will give you the total number of goals in the game, and whichever market code you need, and that should get you there.
Hope that helps!