condition mean min max ZT0-3 11.567503 11.567503 11.567503 ZT4-7 11.2316975 11.2316975 11.2316975 ZT8-11 10.579104000000001 10.579104000000001 10.579104000000001 ZT12-15 10.4949925 10.4949925 10.4949925 ZT16-19 11.928504499999999 11.928504499999999 11.928504499999999 ZT20-23 10.710054 10.710054 10.710054