condition mean min max ZT0-3 4.079585 4.079585 4.079585 ZT4-7 12.936399999999999 12.936399999999999 12.936399999999999 ZT8-11 6.3082 6.3082 6.3082 ZT12-15 3.406455 3.406455 3.406455 ZT16-19 2.27709 2.27709 2.27709 ZT20-23 1.12485 1.12485 1.12485