condition mean min max ZT0-3 10.048779 10.048779 10.048779 ZT4-7 9.763618999999998 9.763618999999998 9.763618999999998 ZT8-11 10.8915565 10.8915565 10.8915565 ZT12-15 10.706325 10.706325 10.706325 ZT16-19 10.5273625 10.5273625 10.5273625 ZT20-23 10.1904525 10.1904525 10.1904525