condition mean min max ZT0-3 18.55 18.55 18.55 ZT4-7 6.8 6.8 6.8 ZT8-11 13.950000000000001 13.950000000000001 13.950000000000001 ZT12-15 14.350000000000001 14.350000000000001 14.350000000000001 ZT16-19 1.1 1.1 1.1 ZT20-23 5.3 5.3 5.3