condition mean min max ZT0-3 10.965136666666666 7.34416 13.042300000000001 ZT4-7 6.7292749999999995 6.7292749999999995 6.7292749999999995 ZT8-11 7.302989999999999 7.302989999999999 7.302989999999999 ZT12-15 9.6450925 8.545235 10.74495 ZT16-19 8.299895 8.299895 8.299895 ZT20-23 11.24045 11.24045 11.24045