condition mean min max ZT0-3 18152.300000000003 18152.300000000003 18152.300000000003 ZT4-7 15999.5 15999.5 15999.5 ZT8-11 16454.1 16454.1 16454.1 ZT12-15 17590.3 17590.3 17590.3 ZT16-19 18415.0 18415.0 18415.0 ZT20-23 18741.9 18741.9 18741.9