condition mean min max ZT0-3 3.774005 3.774005 3.774005 ZT4-7 2.29748 2.29748 2.29748 ZT8-11 4.087479999999999 4.087479999999999 4.087479999999999 ZT12-15 6.873060000000001 6.873060000000001 6.873060000000001 ZT16-19 8.345125 8.345125 8.345125 ZT20-23 6.9708749999999995 6.9708749999999995 6.9708749999999995