condition mean min max ZT0-3 5.6214949999999995 5.6214949999999995 5.6214949999999995 ZT4-7 4.849005 4.849005 4.849005 ZT8-11 5.58266 5.58266 5.58266 ZT12-15 6.46066 6.46066 6.46066 ZT16-19 8.10038 8.10038 8.10038 ZT20-23 6.251945 6.251945 6.251945