condition mean min max ZT0-3 226.456151 226.456151 226.456151 ZT4-7 187.8031645 187.8031645 187.8031645 ZT8-11 173.62314750000002 173.62314750000002 173.62314750000002 ZT12-15 156.78587 156.78587 156.78587 ZT16-19 157.9328795 157.9328795 157.9328795 ZT20-23 176.392827 176.392827 176.392827