condition mean min max ZT0-3 1.101208 0.8274245 1.37569 ZT4-7 1.4137 1.4137 1.4137 ZT8-11 3.1232949999999997 3.1232949999999997 3.1232949999999997 ZT12-15 5.8084125 5.093225 6.5236 ZT16-19 3.3432950000000003 3.3432950000000003 3.3432950000000003 ZT20-23 3.055365 3.055365 3.055365