condition mean min max ZT0-3 7.30963 7.30963 7.30963 ZT4-7 9.122082500000001 9.122082500000001 9.122082500000001 ZT8-11 8.414238000000001 8.414238000000001 8.414238000000001 ZT12-15 8.380661499999999 8.380661499999999 8.380661499999999 ZT16-19 8.031646 8.031646 8.031646 ZT20-23 8.782099500000001 8.782099500000001 8.782099500000001