condition mean min max ZT0-3 9.522885 9.522885 9.522885 ZT4-7 5.760540000000001 5.760540000000001 5.760540000000001 ZT8-11 7.50065 7.50065 7.50065 ZT12-15 9.877659999999999 9.877659999999999 9.877659999999999 ZT16-19 12.4855 12.4855 12.4855 ZT20-23 11.961400000000001 11.961400000000001 11.961400000000001