condition mean min max ZT0-3 5.0456475 4.9672 5.1240950000000005 ZT4-7 6.98628 6.98628 6.98628 ZT8-11 3.99398 3.99398 3.99398 ZT12-15 0 0 0 ZT16-19 5.522195 5.522195 5.522195 ZT20-23 7.8454 7.8454 7.8454