condition mean min max ZT0-3 2.578475 2.578475 2.578475 ZT4-7 2.036035 2.036035 2.036035 ZT8-11 2.8244 2.8244 2.8244 ZT12-15 2.8041799999999997 2.8041799999999997 2.8041799999999997 ZT16-19 3.33066 3.33066 3.33066 ZT20-23 2.350305 2.350305 2.350305