condition mean min max ZT0-3 7.67237 7.67237 7.67237 ZT4-7 7.1048849999999995 7.1048849999999995 7.1048849999999995 ZT8-11 7.5701350000000005 7.5701350000000005 7.5701350000000005 ZT12-15 7.790735 7.790735 7.790735 ZT16-19 9.16997 9.16997 9.16997 ZT20-23 7.44261 7.44261 7.44261