condition mean min max ZT0-3 0.31050916666666667 0.1684835 0.4486595 ZT4-7 0.21790500000000002 0.21790500000000002 0.21790500000000002 ZT8-11 0.3626795 0.3626795 0.3626795 ZT12-15 1.8766395 0.960144 2.793135 ZT16-19 0.6587099999999999 0.6587099999999999 0.6587099999999999 ZT20-23 0.63015 0.63015 0.63015