condition mean min max ZT0-3 0.531505 0.531505 0.531505 ZT4-7 0.3066605 0.3066605 0.3066605 ZT8-11 1.95954 1.95954 1.95954 ZT12-15 5.42286 5.42286 5.42286 ZT16-19 2.233715 2.233715 2.233715 ZT20-23 1.163745 1.163745 1.163745