condition mean min max ZT0-3 1.218245 1.195725 1.2407650000000001 ZT4-7 0.6442645 0.6442645 0.6442645 ZT8-11 0.6104275 0.6104275 0.6104275 ZT12-15 0 0 0 ZT16-19 1.2361849999999999 1.2361849999999999 1.2361849999999999 ZT20-23 1.514125 1.514125 1.514125