condition mean min max ZT0-3 0.401818 0.401818 0.401818 ZT4-7 1.0784715 1.0784715 1.0784715 ZT8-11 1.390435 1.390435 1.390435 ZT12-15 0.804605 0.804605 0.804605 ZT16-19 1.013714 1.013714 1.013714 ZT20-23 0.26938 0.26938 0.26938