condition mean min max ZT0-3 1.658563 1.079824 2.05625 ZT4-7 1.803455 1.803455 1.803455 ZT8-11 1.585385 1.585385 1.585385 ZT12-15 1.254724 1.246115 1.263333 ZT16-19 1.30305 1.30305 1.30305 ZT20-23 1.581305 1.581305 1.581305