condition mean min max ZT0-3 1.36210487175 1.3584152025 1.3657945409999999 ZT4-7 1.37693790025 1.059634402 1.6942413985 ZT8-11 1.6575721485000001 1.637245456 1.6778988410000002 ZT12-15 1.300486314 1.229302921 1.3716697070000001 ZT16-19 1.5403352895000002 1.223766036 1.8569045430000002 ZT20-23 3.3996288025 2.788389124 4.010868481