condition mean min max ZT0-3 26.119666666666667 20.4758 33.7486 ZT4-7 10.63724 10.63724 10.63724 ZT8-11 18.4114 18.4114 18.4114 ZT12-15 19.40475 13.51905 25.29045 ZT16-19 26.215600000000002 26.215600000000002 26.215600000000002 ZT20-23 21.60625 21.60625 21.60625