condition mean min max ZT0-3 17.646250000000002 17.00415 18.28835 ZT4-7 16.191200000000002 16.191200000000002 16.191200000000002 ZT8-11 14.56865 14.56865 14.56865 ZT12-15 0 0 0 ZT16-19 16.26245 16.26245 16.26245 ZT20-23 20.10935 20.10935 20.10935