condition mean min max ZT0-3 1.6748266666666667 1.17287 1.99066 ZT4-7 1.13405 1.13405 1.13405 ZT8-11 0.62097 0.62097 0.62097 ZT12-15 1.3294175 1.29873 1.360105 ZT16-19 1.534605 1.534605 1.534605 ZT20-23 1.648355 1.648355 1.648355