condition mean min max ZT0-3 15.472349999999999 15.472349999999999 15.472349999999999 ZT4-7 9.880665 9.880665 9.880665 ZT8-11 11.86335 11.86335 11.86335 ZT12-15 16.842950000000002 16.842950000000002 16.842950000000002 ZT16-19 21.9769 21.9769 21.9769 ZT20-23 20.4025 20.4025 20.4025