condition mean min max ZT0-3 28.484676 28.484676 28.484676 ZT4-7 35.422009 35.422009 35.422009 ZT8-11 54.625067 54.625067 54.625067 ZT12-15 49.67542 49.67542 49.67542 ZT16-19 58.220292 58.220292 58.220292 ZT20-23 53.789375 53.789375 53.789375