condition mean min max ZT0-3 5.539948333333333 4.205995 6.242430000000001 ZT4-7 4.32789 4.32789 4.32789 ZT8-11 3.47142 3.47142 3.47142 ZT12-15 10.69609 9.78268 11.6095 ZT16-19 4.99277 4.99277 4.99277 ZT20-23 7.556215 7.556215 7.556215