condition mean min max ZT0-3 226.735181 226.735181 226.735181 ZT4-7 208.75591150000002 208.75591150000002 208.75591150000002 ZT8-11 189.406252 189.406252 189.406252 ZT12-15 206.6919555 206.6919555 206.6919555 ZT16-19 189.690362 189.690362 189.690362 ZT20-23 199.3149645 199.3149645 199.3149645