condition mean min max ZT0-3 9.395211 9.395211 9.395211 ZT4-7 11.372106 11.372106 11.372106 ZT8-11 10.581118 10.581118 10.581118 ZT12-15 10.0206685 10.0206685 10.0206685 ZT16-19 9.559593 9.559593 9.559593 ZT20-23 9.759393 9.759393 9.759393