condition mean min max ZT0-3 3.65812 3.65812 3.65812 ZT4-7 0.8168165000000001 0.8168165000000001 0.8168165000000001 ZT8-11 3.655375 3.655375 3.655375 ZT12-15 8.784355 8.784355 8.784355 ZT16-19 11.581733333333332 11.581733333333332 11.581733333333332 ZT20-23 7.59285 7.59285 7.59285