condition mean min max ZT0-3 9.801352 9.801352 9.801352 ZT4-7 7.933171 7.933171 7.933171 ZT8-11 8.008772 8.008772 8.008772 ZT12-15 9.210239 9.210239 9.210239 ZT16-19 8.8720945 8.8720945 8.8720945 ZT20-23 8.0714145 8.0714145 8.0714145