condition mean min max ZT0-3 7.632786666666666 7.632786666666666 7.632786666666666 ZT4-7 3.082615 3.082615 3.082615 ZT8-11 1.3732704999999998 1.3732704999999998 1.3732704999999998 ZT12-15 2.92185 2.92185 2.92185 ZT16-19 7.01957 7.01957 7.01957 ZT20-23 8.21373 8.21373 8.21373