condition mean min max ZT0-3 6.537521666666667 5.2476899999999995 7.27919 ZT4-7 5.02377 5.02377 5.02377 ZT8-11 6.1082350000000005 6.1082350000000005 6.1082350000000005 ZT12-15 9.3246225 7.15458 11.494665000000001 ZT16-19 10.210474999999999 10.210474999999999 10.210474999999999 ZT20-23 9.43914 9.43914 9.43914