condition mean min max ZT0-3 4.026680000000001 4.026680000000001 4.026680000000001 ZT4-7 3.2009049999999997 3.2009049999999997 3.2009049999999997 ZT8-11 3.07442 3.07442 3.07442 ZT12-15 3.3394649999999997 3.3394649999999997 3.3394649999999997 ZT16-19 4.7411449999999995 4.7411449999999995 4.7411449999999995 ZT20-23 3.6051 3.6051 3.6051