condition mean min max ZT0-3 5.388976666666666 4.420685 6.68233 ZT4-7 4.0374 4.0374 4.0374 ZT8-11 8.007645 8.007645 8.007645 ZT12-15 10.602905 10.020859999999999 11.18495 ZT16-19 12.84495 12.84495 12.84495 ZT20-23 9.515585 9.515585 9.515585