condition mean min max ZT0-3 7.8476325 7.502314999999999 8.19295 ZT4-7 8.568465 8.568465 8.568465 ZT8-11 10.635380000000001 10.635380000000001 10.635380000000001 ZT12-15 0 0 0 ZT16-19 12.54745 12.54745 12.54745 ZT20-23 10.8601 10.8601 10.8601