condition mean min max ZT0-3 49.435913 49.435913 49.435913 ZT4-7 22.8682205 22.8682205 22.8682205 ZT8-11 16.1877445 16.1877445 16.1877445 ZT12-15 23.360344 23.360344 23.360344 ZT16-19 16.199113 16.199113 16.199113 ZT20-23 19.55901 19.55901 19.55901