I'm sure milk from individual mothers can
vary by a few percent in carbs and fat, less in protein.
14CO varies by factor of two or more over the seasonal cycle, whereas methyl chloroform only
varies by a few percent.
Not exact matches
The gains
vary by application, but estimates range from 5 - 10
percent, give or take a
few.
Surface pressures on the Earth
vary all of the time,
by a
few percent.
The total annual dosage, averaged over the entire surface,
varies by up to 0.1
percent, while more specific, seasonal changes at any place can reach a
few percent.