condition mean min max ZT0-3 8.1756525 7.267925 9.08338 ZT4-7 14.88525 14.88525 14.88525 ZT8-11 11.194949999999999 11.194949999999999 11.194949999999999 ZT12-15 0 0 0 ZT16-19 13.588000000000001 13.588000000000001 13.588000000000001 ZT20-23 12.62715 12.62715 12.62715