condition mean min max ZT0-3 8.992303 8.992303 8.992303 ZT4-7 9.133790000000001 9.133790000000001 9.133790000000001 ZT8-11 9.385345000000001 9.385345000000001 9.385345000000001 ZT12-15 8.931150500000001 8.931150500000001 8.931150500000001 ZT16-19 9.0732745 9.0732745 9.0732745 ZT20-23 9.516482499999999 9.516482499999999 9.516482499999999