condition mean min max ZT0-3 8.946096 8.946096 8.946096 ZT4-7 8.1001645 8.1001645 8.1001645 ZT8-11 8.9910545 8.9910545 8.9910545 ZT12-15 8.7599075 8.7599075 8.7599075 ZT16-19 8.489553 8.489553 8.489553 ZT20-23 8.918716 8.918716 8.918716