condition mean min max ZT0-3 3.4941899999999997 3.4941899999999997 3.4941899999999997 ZT4-7 2.20105 2.20105 2.20105 ZT8-11 5.136464999999999 5.136464999999999 5.136464999999999 ZT12-15 6.48573 6.48573 6.48573 ZT16-19 4.2703299999999995 4.2703299999999995 4.2703299999999995 ZT20-23 4.020255000000001 4.020255000000001 4.020255000000001