condition mean min max ZT0-3 5.23355 5.23355 5.23355 ZT4-7 3.72229 3.72229 3.72229 ZT8-11 5.48961 5.48961 5.48961 ZT12-15 6.21877 6.21877 6.21877 ZT16-19 8.17615 8.17615 8.17615 ZT20-23 7.13536 7.13536 7.13536