condition mean min max ZT0-3 75.340885 75.340885 75.340885 ZT4-7 165.5456355 165.5456355 165.5456355 ZT8-11 180.277264 180.277264 180.277264 ZT12-15 390.230138 390.230138 390.230138 ZT16-19 459.45901950000007 459.45901950000007 459.45901950000007 ZT20-23 580.63331 580.63331 580.63331