condition mean min max ZT0-3 6.3573450000000005 6.3573450000000005 6.3573450000000005 ZT4-7 9.498435 9.498435 9.498435 ZT8-11 7.092725 7.092725 7.092725 ZT12-15 9.63756 9.63756 9.63756 ZT16-19 4.149315 4.149315 4.149315 ZT20-23 4.171 4.171 4.171