condition mean min max ZT0-3 26.94445 25.6558 28.2331 ZT4-7 23.9488 23.9488 23.9488 ZT8-11 28.17395 28.17395 28.17395 ZT12-15 0 0 0 ZT16-19 33.35365 33.35365 33.35365 ZT20-23 37.1299 37.1299 37.1299