condition mean min max ZT0-3 15.347517 15.347517 15.347517 ZT4-7 15.44978 15.44978 15.44978 ZT8-11 13.481872 13.481872 13.481872 ZT12-15 15.135833 15.135833 15.135833 ZT16-19 13.802535500000001 13.802535500000001 13.802535500000001 ZT20-23 14.337090499999999 14.337090499999999 14.337090499999999