condition mean min max ZT0-3 7.6478649999999995 6.7922 8.50353 ZT4-7 5.143815 5.143815 5.143815 ZT8-11 2.600315 2.600315 2.600315 ZT12-15 0 0 0 ZT16-19 3.595355 3.595355 3.595355 ZT20-23 3.684235 3.684235 3.684235