condition mean min max ZT0-3 21.778950000000002 21.778950000000002 21.778950000000002 ZT4-7 22.931600000000003 22.931600000000003 22.931600000000003 ZT8-11 22.57245 22.57245 22.57245 ZT12-15 23.21215 23.21215 23.21215 ZT16-19 22.230649999999997 22.230649999999997 22.230649999999997 ZT20-23 18.25295 18.25295 18.25295