condition mean min max ZT0-3 2.8058256666666668 1.507517 4.42155 ZT4-7 1.2429815 1.2429815 1.2429815 ZT8-11 1.20313 1.20313 1.20313 ZT12-15 2.8502925 2.69132 3.009265 ZT16-19 3.703995 3.703995 3.703995 ZT20-23 4.711685 4.711685 4.711685