condition mean min max ZT0-3 2.45 2.45 2.45 ZT4-7 1.0 1.0 1.0 ZT8-11 5.550000000000001 5.550000000000001 5.550000000000001 ZT12-15 3.9499999999999997 3.9499999999999997 3.9499999999999997 ZT16-19 9.5 9.5 9.5 ZT20-23 10.049999999999999 10.049999999999999 10.049999999999999