condition mean min max ZT0-3 1.5688616666666668 1.4613450000000001 1.632635 ZT4-7 1.442785 1.442785 1.442785 ZT8-11 1.037614 1.037614 1.037614 ZT12-15 1.5338150000000002 1.390505 1.6771250000000002 ZT16-19 1.56961 1.56961 1.56961 ZT20-23 2.003665 2.003665 2.003665