condition mean min max ZT0-3 9.370575 9.370575 9.370575 ZT4-7 13.577138999999999 13.577138999999999 13.577138999999999 ZT8-11 11.986552 11.986552 11.986552 ZT12-15 11.818067500000002 11.818067500000002 11.818067500000002 ZT16-19 11.330614 11.330614 11.330614 ZT20-23 11.185021500000001 11.185021500000001 11.185021500000001