condition mean min max ZT0-3 18.66985 18.1373 19.2024 ZT4-7 20.34785 20.34785 20.34785 ZT8-11 21.37225 21.37225 21.37225 ZT12-15 0 0 0 ZT16-19 25.938000000000002 25.938000000000002 25.938000000000002 ZT20-23 21.87695 21.87695 21.87695