condition mean min max ZT0-3 3.87189 3.87189 3.87189 ZT4-7 2.661775 2.661775 2.661775 ZT8-11 2.8059200000000004 2.8059200000000004 2.8059200000000004 ZT12-15 4.082085 4.082085 4.082085 ZT16-19 5.146815 5.146815 5.146815 ZT20-23 4.153465 4.153465 4.153465