condition mean min max ZT0-3 5.8637500000000005 5.79494 5.9325600000000005 ZT4-7 5.37476 5.37476 5.37476 ZT8-11 3.757355 3.757355 3.757355 ZT12-15 0 0 0 ZT16-19 4.099335 4.099335 4.099335 ZT20-23 3.489065 3.489065 3.489065