condition mean min max ZT0-3 12.778647 12.778647 12.778647 ZT4-7 13.74623 13.74623 13.74623 ZT8-11 13.0558445 13.0558445 13.0558445 ZT12-15 11.1257635 11.1257635 11.1257635 ZT16-19 13.446882500000001 13.446882500000001 13.446882500000001 ZT20-23 13.1959615 13.1959615 13.1959615