condition mean min max ZT0-3 1.9383042447499998 1.7082681704999998 2.168340319 ZT4-7 2.3148739464999997 2.005423701 2.624324192 ZT8-11 2.3263871199999997 2.1219033355 2.5308709045 ZT12-15 2.3613530647500003 2.2103427015 2.512363428 ZT16-19 2.17568148325 1.898080369 2.4532825975 ZT20-23 3.59869045425 3.2041513019999996 3.9932296065