condition mean min max ZT0-3 1.4157075000000001 1.3777650000000001 1.45365 ZT4-7 2.25482 2.25482 2.25482 ZT8-11 2.255195 2.255195 2.255195 ZT12-15 0 0 0 ZT16-19 2.8033900000000003 2.8033900000000003 2.8033900000000003 ZT20-23 3.632545 3.632545 3.632545