condition mean min max ZT0-3 6.06466 6.04814 6.08118 ZT4-7 7.01477 7.01477 7.01477 ZT8-11 7.031280000000001 7.031280000000001 7.031280000000001 ZT12-15 0 0 0 ZT16-19 6.98299 6.98299 6.98299 ZT20-23 7.539490000000001 7.539490000000001 7.539490000000001