condition mean min max ZT0-3 2.4455675 1.680985 3.21015 ZT4-7 3.8249450000000005 3.8249450000000005 3.8249450000000005 ZT8-11 3.085635 3.085635 3.085635 ZT12-15 0 0 0 ZT16-19 11.22955 11.22955 11.22955 ZT20-23 11.4408 11.4408 11.4408