condition mean min max ZT0-3 2.791955 2.790655 2.7932550000000003 ZT4-7 3.222575 3.222575 3.222575 ZT8-11 1.72046 1.72046 1.72046 ZT12-15 0 0 0 ZT16-19 1.84475 1.84475 1.84475 ZT20-23 2.3656800000000002 2.3656800000000002 2.3656800000000002