condition mean min max ZT0-3 28.217025 28.2001 28.23395 ZT4-7 28.7255 28.7255 28.7255 ZT8-11 50.981700000000004 50.981700000000004 50.981700000000004 ZT12-15 0 0 0 ZT16-19 51.14265 51.14265 51.14265 ZT20-23 37.85975 37.85975 37.85975