condition mean min max ZT0-3 21.274604 21.274604 21.274604 ZT4-7 39.4529395 39.4529395 39.4529395 ZT8-11 39.298632 39.298632 39.298632 ZT12-15 31.837926000000003 31.837926000000003 31.837926000000003 ZT16-19 39.9089635 39.9089635 39.9089635 ZT20-23 30.144373 30.144373 30.144373