condition mean min max ZT0-3 10.418586666666666 6.1136099999999995 12.67555 ZT4-7 5.239385 5.239385 5.239385 ZT8-11 8.026935 8.026935 8.026935 ZT12-15 12.134174999999999 12.132249999999999 12.136099999999999 ZT16-19 12.0089 12.0089 12.0089 ZT20-23 15.57905 15.57905 15.57905