condition mean min max ZT0-3 1.6589866666666668 1.4360050000000002 1.82091 ZT4-7 0.9273795 0.9273795 0.9273795 ZT8-11 1.0371934999999999 1.0371934999999999 1.0371934999999999 ZT12-15 2.6616425 2.534935 2.78835 ZT16-19 2.978625 2.978625 2.978625 ZT20-23 2.77399 2.77399 2.77399