condition mean min max ZT0-3 2.396383333333333 2.396383333333333 2.396383333333333 ZT4-7 3.22658 3.22658 3.22658 ZT8-11 1.1938600000000001 1.1938600000000001 1.1938600000000001 ZT12-15 1.44026 1.44026 1.44026 ZT16-19 1.4842950000000001 1.4842950000000001 1.4842950000000001 ZT20-23 0.0 0.0 0.0