condition mean min max ZT0-3 2.11214 2.11214 2.11214 ZT4-7 1.565585 1.565585 1.565585 ZT8-11 1.888185 1.888185 1.888185 ZT12-15 2.3350850000000003 2.3350850000000003 2.3350850000000003 ZT16-19 3.38397 3.38397 3.38397 ZT20-23 2.87438 2.87438 2.87438