condition mean min max ZT0-3 31.744463 31.744463 31.744463 ZT4-7 29.9400585 29.9400585 29.9400585 ZT8-11 29.110215500000002 29.110215500000002 29.110215500000002 ZT12-15 31.0160325 31.0160325 31.0160325 ZT16-19 34.6895045 34.6895045 34.6895045 ZT20-23 31.696944000000002 31.696944000000002 31.696944000000002