condition mean min max ZT0-3 3.93081 3.93081 3.93081 ZT4-7 3.1024450000000003 3.1024450000000003 3.1024450000000003 ZT8-11 4.12923 4.12923 4.12923 ZT12-15 2.6543650000000003 2.6543650000000003 2.6543650000000003 ZT16-19 6.461774999999999 6.461774999999999 6.461774999999999 ZT20-23 4.22548 4.22548 4.22548