condition mean min max ZT0-3 2.80315 2.57608 3.03022 ZT4-7 3.9554 3.9554 3.9554 ZT8-11 4.93936 4.93936 4.93936 ZT12-15 0 0 0 ZT16-19 5.7665500000000005 5.7665500000000005 5.7665500000000005 ZT20-23 5.15726 5.15726 5.15726