condition mean min max ZT0-3 20.970625 20.970625 20.970625 ZT4-7 30.4563795 30.4563795 30.4563795 ZT8-11 33.6704435 33.6704435 33.6704435 ZT12-15 36.796458 36.796458 36.796458 ZT16-19 25.566417 25.566417 25.566417 ZT20-23 21.103063 21.103063 21.103063