condition mean min max ZT0-3 5.666496666666666 3.3678 7.044795 ZT4-7 3.572575 3.572575 3.572575 ZT8-11 4.07135 4.07135 4.07135 ZT12-15 5.2090525 5.0860199999999995 5.332085 ZT16-19 5.41791 5.41791 5.41791 ZT20-23 8.109770000000001 8.109770000000001 8.109770000000001