condition mean min max ZT0-3 12.576902 12.576902 12.576902 ZT4-7 12.1736605 12.1736605 12.1736605 ZT8-11 8.817933 8.817933 8.817933 ZT12-15 12.015078500000001 12.015078500000001 12.015078500000001 ZT16-19 10.604897000000001 10.604897000000001 10.604897000000001 ZT20-23 11.177392 11.177392 11.177392