condition mean min max ZT0-3 9.7299375 8.621275 10.8386 ZT4-7 12.6733 12.6733 12.6733 ZT8-11 16.05025 16.05025 16.05025 ZT12-15 0 0 0 ZT16-19 21.31625 21.31625 21.31625 ZT20-23 15.58215 15.58215 15.58215