condition mean min max ZT0-3 24.695233 24.695233 24.695233 ZT4-7 29.859943 29.859943 29.859943 ZT8-11 33.3252455 33.3252455 33.3252455 ZT12-15 31.486525 31.486525 31.486525 ZT16-19 31.949554 31.949554 31.949554 ZT20-23 30.576631 30.576631 30.576631