condition mean min max ZT0-3 6.6078175 6.298425 6.917210000000001 ZT4-7 4.664335 4.664335 4.664335 ZT8-11 6.587815 6.587815 6.587815 ZT12-15 0 0 0 ZT16-19 16.74615 16.74615 16.74615 ZT20-23 11.2502 11.2502 11.2502