condition mean min max ZT0-3 89.301537 89.301537 89.301537 ZT4-7 61.852708 61.852708 61.852708 ZT8-11 68.440799 68.440799 68.440799 ZT12-15 133.0279905 133.0279905 133.0279905 ZT16-19 114.8602205 114.8602205 114.8602205 ZT20-23 205.983859 205.983859 205.983859