condition mean min max ZT0-3 9.225195 8.676755 9.773635 ZT4-7 4.313855 4.313855 4.313855 ZT8-11 1.419685 1.419685 1.419685 ZT12-15 0 0 0 ZT16-19 2.84495 2.84495 2.84495 ZT20-23 8.51074 8.51074 8.51074