(back_amount + IF(back_price2 >= r_ticks(back_price, -4), back_amount2, 0) + IF(back_price3 >= r_ticks(back_price, -4), back_amount3, 0))/(lay_amount + IF(lay_price2 <= r_ticks(lay_price, 4), lay_amount2, 0) + IF(lay_price3 <= r_ticks(lay_price, 4), lay_amount3, 0))