condition mean min max ZT0-3 3.7578725000000004 3.509655 4.00609 ZT4-7 2.67131 2.67131 2.67131 ZT8-11 4.017295 4.017295 4.017295 ZT12-15 0 0 0 ZT16-19 4.596295 4.596295 4.596295 ZT20-23 4.95079 4.95079 4.95079