condition mean min max ZT0-3 9.340665 9.340665 9.340665 ZT4-7 9.192506999999999 9.192506999999999 9.192506999999999 ZT8-11 8.930695 8.930695 8.930695 ZT12-15 8.330286999999998 8.330286999999998 8.330286999999998 ZT16-19 8.298413 8.298413 8.298413 ZT20-23 9.570389500000001 9.570389500000001 9.570389500000001