condition mean min max ZT0-3 8.294035000000001 7.45429 9.13378 ZT4-7 4.34752 4.34752 4.34752 ZT8-11 2.8614 2.8614 2.8614 ZT12-15 0 0 0 ZT16-19 6.069295 6.069295 6.069295 ZT20-23 9.40254 9.40254 9.40254