condition mean min max ZT0-3 18.9513 18.9513 18.9513 ZT4-7 15.8963 15.8963 15.8963 ZT8-11 11.48647 11.48647 11.48647 ZT12-15 11.073450000000001 11.073450000000001 11.073450000000001 ZT16-19 12.2829 12.2829 12.2829 ZT20-23 15.4871 15.4871 15.4871