For example, you could reframe in terms of the percent change: “The number of children having a traditional stay-at-home mom decreased more than 50% between 1970 and 2012.” I advise caution, however, any time you reduce from multiple numbers down to a single one—think about what context may be lost in doing so. In this case, I find that the actual magnitude of the numbers (20% and 41%) is helpful in interpreting and understanding the change.
