condition mean min max ZT0-3 23.278807 23.278807 23.278807 ZT4-7 15.577611 15.577611 15.577611 ZT8-11 14.060676 14.060676 14.060676 ZT12-15 13.21999 13.21999 13.21999 ZT16-19 17.629493 17.629493 17.629493 ZT20-23 22.057551500000002 22.057551500000002 22.057551500000002