condition mean min max ZT0-3 7.133213333333333 5.757235 9.183029999999999 ZT4-7 7.177770000000001 7.177770000000001 7.177770000000001 ZT8-11 7.859285 7.859285 7.859285 ZT12-15 6.4854424999999996 5.5967199999999995 7.374165 ZT16-19 6.908704999999999 6.908704999999999 6.908704999999999 ZT20-23 7.2246500000000005 7.2246500000000005 7.2246500000000005