condition mean min max ZT0-3 16.81595 16.81595 16.81595 ZT4-7 7.18993 7.18993 7.18993 ZT8-11 30.7999 30.7999 30.7999 ZT12-15 62.05385 62.05385 62.05385 ZT16-19 58.58865 58.58865 58.58865 ZT20-23 45.22745 45.22745 45.22745