condition mean min max ZT0-3 3.362236666666667 2.5215 3.8538550000000003 ZT4-7 3.14855 3.14855 3.14855 ZT8-11 3.29629 3.29629 3.29629 ZT12-15 3.37667 2.82298 3.93036 ZT16-19 3.4973850000000004 3.4973850000000004 3.4973850000000004 ZT20-23 4.30833 4.30833 4.30833