condition mean min max ZT0-3 49.997546 49.997546 49.997546 ZT4-7 25.7349915 25.7349915 25.7349915 ZT8-11 25.1260045 25.1260045 25.1260045 ZT12-15 28.9347375 28.9347375 28.9347375 ZT16-19 21.548039000000003 21.548039000000003 21.548039000000003 ZT20-23 24.025844 24.025844 24.025844