condition mean min max ZT0-3 21.661906 21.661906 21.661906 ZT4-7 19.9763425 19.9763425 19.9763425 ZT8-11 24.774756 24.774756 24.774756 ZT12-15 23.749555 23.749555 23.749555 ZT16-19 20.8590395 20.8590395 20.8590395 ZT20-23 19.493557 19.493557 19.493557