condition mean min max ZT0-3 6.877558333333333 6.29936 7.276959999999999 ZT4-7 6.66306 6.66306 6.66306 ZT8-11 4.593745 4.593745 4.593745 ZT12-15 8.385390000000001 6.73742 10.03336 ZT16-19 6.73631 6.73631 6.73631 ZT20-23 8.677365 8.677365 8.677365