condition mean min max ZT0-3 1.570474 1.570474 1.570474 ZT4-7 1.4344815 1.4344815 1.4344815 ZT8-11 1.3967195 1.3967195 1.3967195 ZT12-15 2.21996 2.21996 2.21996 ZT16-19 1.6605699999999999 1.6605699999999999 1.6605699999999999 ZT20-23 2.40819 2.40819 2.40819