condition mean min max ZT0-3 6.608525 3.939865 9.277185 ZT4-7 28.26945 28.26945 28.26945 ZT8-11 9.16217 9.16217 9.16217 ZT12-15 0 0 0 ZT16-19 2.386615 2.386615 2.386615 ZT20-23 6.29149 6.29149 6.29149