condition mean min max ZT0-3 2.0113525 1.996905 2.0258000000000003 ZT4-7 1.922765 1.922765 1.922765 ZT8-11 1.665415 1.665415 1.665415 ZT12-15 0 0 0 ZT16-19 2.3911 2.3911 2.3911 ZT20-23 2.4011 2.4011 2.4011