condition mean min max ZT0-3 13.579211666666668 8.384885 16.70815 ZT4-7 9.15572 9.15572 9.15572 ZT8-11 10.3879 10.3879 10.3879 ZT12-15 12.8219 12.77415 12.86965 ZT16-19 16.02785 16.02785 16.02785 ZT20-23 22.15265 22.15265 22.15265