condition mean min max ZT0-3 3.6411100000000003 3.6411100000000003 3.6411100000000003 ZT4-7 1.80141 1.80141 1.80141 ZT8-11 1.8317999999999999 1.8317999999999999 1.8317999999999999 ZT12-15 3.70959 3.70959 3.70959 ZT16-19 7.442080000000001 7.442080000000001 7.442080000000001 ZT20-23 5.44503 5.44503 5.44503