condition mean min max ZT0-3 1.1177385 0.8722405 1.4115 ZT4-7 0.6914875 0.6914875 0.6914875 ZT8-11 0.7701290000000001 0.7701290000000001 0.7701290000000001 ZT12-15 1.1036912499999998 1.0971099999999998 1.1102725 ZT16-19 0.8815185 0.8815185 0.8815185 ZT20-23 1.0763505 1.0763505 1.0763505