The thing is, you can't be delinquent when you aren't required to make payments, so if you divide the number of delinquent student loans by the total amount of outstanding debt including loans in deferment and forbearance, you are comparing apples to oranges. Only around 55% of outstanding student loans are in repayment, and obviously, what we really want to know is what percentage of those loans are delinquent. We don't care what percentage of total outstanding student debt is delinquent because 45% of borrowers aren't yet required to make payments so it makes absolutely no sense to include them in the equation — we know what percentage of that group is delinquent, it's 0%, because no one is asking them for any money yet. 

What we can do though, is divide the amount of debt that's delinquent by the total amount of debt in repayment and then extrapolate from that and say something like this: "If 55% of total student debt is currently in repayment and 27% of that is delinquent, then it seems reasonable to assume that a similar rate will prevail for the other 45% of borrowers once they go into repayment unless something changes in the economy which it won't, so in all likelihood, about 1 in 3 student borrowers will end up 30 or more days delinquent and that adds up to about $400 billion in student debt that likely won't be in good standing."

This is particularly bad news when you consider that "the TBAC forecasts, in its worst economic case scenario for the millennial generation (which sadly, based on recent employment and income trends for America's young adults is more like the base case scenario), total student loans, which currently stand a little over $1 trillion (or more than all the credit card debt in America), is set to triple in just the next decade, hitting a whopping $3.3 trillion by 2024."