condition mean min max ZT0-3 8.809665 7.55038 10.068950000000001 ZT4-7 10.553825 10.553825 10.553825 ZT8-11 12.132850000000001 12.132850000000001 12.132850000000001 ZT12-15 0 0 0 ZT16-19 15.75085 15.75085 15.75085 ZT20-23 11.69365 11.69365 11.69365