condition mean min max ZT0-3 1.228007 0.62171 2.12129 ZT4-7 0.9721315 0.9721315 0.9721315 ZT8-11 0.77779 0.77779 0.77779 ZT12-15 0.7656587499999999 0.3561075 1.1752099999999999 ZT16-19 1.237595 1.237595 1.237595 ZT20-23 1.01506 1.01506 1.01506