condition mean min max ZT0-3 24.877275 15.5353 34.21925 ZT4-7 29.49025 29.49025 29.49025 ZT8-11 2.56633 2.56633 2.56633 ZT12-15 0 0 0 ZT16-19 1.348304 1.348304 1.348304 ZT20-23 26.27035 26.27035 26.27035