condition mean min max ZT0-3 2.07239 2.07239 2.07239 ZT4-7 1.89306 1.89306 1.89306 ZT8-11 1.1401715000000001 1.1401715000000001 1.1401715000000001 ZT12-15 1.39535 1.39535 1.39535 ZT16-19 1.4243350000000001 1.4243350000000001 1.4243350000000001 ZT20-23 1.552465 1.552465 1.552465