condition mean min max ZT0-3 651.020219 651.020219 651.020219 ZT4-7 668.121653 668.121653 668.121653 ZT8-11 676.216325 676.216325 676.216325 ZT12-15 689.798669 689.798669 689.798669 ZT16-19 583.26575 583.26575 583.26575 ZT20-23 572.5464335 572.5464335 572.5464335