condition mean min max ZT0-3 8.585754999999999 8.585754999999999 8.585754999999999 ZT4-7 5.517735 5.517735 5.517735 ZT8-11 7.0049399999999995 7.0049399999999995 7.0049399999999995 ZT12-15 9.127255000000002 9.127255000000002 9.127255000000002 ZT16-19 10.578949999999999 10.578949999999999 10.578949999999999 ZT20-23 9.4021 9.4021 9.4021