condition mean min max ZT0-3 21.266550000000002 21.162750000000003 21.370350000000002 ZT4-7 16.86305 16.86305 16.86305 ZT8-11 21.72605 21.72605 21.72605 ZT12-15 0 0 0 ZT16-19 23.470950000000002 23.470950000000002 23.470950000000002 ZT20-23 22.717950000000002 22.717950000000002 22.717950000000002