condition mean min max ZT0-3 16.8407 15.355599999999999 18.3258 ZT4-7 7.439115 7.439115 7.439115 ZT8-11 5.23898 5.23898 5.23898 ZT12-15 0 0 0 ZT16-19 6.81221 6.81221 6.81221 ZT20-23 10.1711 10.1711 10.1711