condition mean min max ZT0-3 4.954395 1.98802 7.046010000000001 ZT4-7 5.637855 5.637855 5.637855 ZT8-11 23.5765 23.5765 23.5765 ZT12-15 21.062525 17.2339 24.891150000000003 ZT16-19 11.4057 11.4057 11.4057 ZT20-23 7.757944999999999 7.757944999999999 7.757944999999999