condition mean min max ZT0-3 5.8287700000000005 5.8287700000000005 5.8287700000000005 ZT4-7 1.8813900000000001 1.8813900000000001 1.8813900000000001 ZT8-11 3.996985 3.996985 3.996985 ZT12-15 9.686435 9.686435 9.686435 ZT16-19 12.5786 12.5786 12.5786 ZT20-23 9.34675 9.34675 9.34675