condition mean min max ZT0-3 2.730415 2.730415 2.730415 ZT4-7 1.38939 1.38939 1.38939 ZT8-11 1.79794 1.79794 1.79794 ZT12-15 1.9929 1.9929 1.9929 ZT16-19 3.753115 3.753115 3.753115 ZT20-23 2.36702 2.36702 2.36702