condition mean min max ZT0-3 20.648506 20.648506 20.648506 ZT4-7 25.717264 25.717264 25.717264 ZT8-11 30.56071 30.56071 30.56071 ZT12-15 29.7198505 29.7198505 29.7198505 ZT16-19 20.771232 20.771232 20.771232 ZT20-23 16.586771499999998 16.586771499999998 16.586771499999998