condition mean min max ZT0-3 9.760295 9.760295 9.760295 ZT4-7 7.5375700000000005 7.5375700000000005 7.5375700000000005 ZT8-11 8.19894 8.19894 8.19894 ZT12-15 10.26905 10.26905 10.26905 ZT16-19 11.2583 11.2583 11.2583 ZT20-23 9.976765 9.976765 9.976765