condition mean min max ZT0-3 2.79931 2.79931 2.79931 ZT4-7 2.0388200000000003 2.0388200000000003 2.0388200000000003 ZT8-11 1.678325 1.678325 1.678325 ZT12-15 3.136655 3.136655 3.136655 ZT16-19 3.02454 3.02454 3.02454 ZT20-23 2.8166450000000003 2.8166450000000003 2.8166450000000003