condition mean min max ZT0-3 2.7225133333333336 1.2402350000000002 5.16994 ZT4-7 1.84182 1.84182 1.84182 ZT8-11 1.37424 1.37424 1.37424 ZT12-15 1.62822 1.449925 1.806515 ZT16-19 1.0830305 1.0830305 1.0830305 ZT20-23 0.7805455 0.7805455 0.7805455