condition mean min max ZT0-3 2.403705 2.39239 2.41502 ZT4-7 5.09532 5.09532 5.09532 ZT8-11 6.6589849999999995 6.6589849999999995 6.6589849999999995 ZT12-15 0 0 0 ZT16-19 4.8526299999999996 4.8526299999999996 4.8526299999999996 ZT20-23 3.497695 3.497695 3.497695