Student-loan debt in the US has grown to a staggering $1.3 trillion, and many policymakers refer to the seemingly inexorable levels of mounting debt as a crisis. Some, like Vermont Sen. Bernie Sanders, and Democratic presidential nominee Hillary Clinton, have suggested plans to provide college for free or at least, minimal cost.

The below chart below shows how quickly college tuition has grown at both private and public universities in the US, using constant 2014-2015 dollars.

In during the 1980-81 school year, the average college tuition at private universities was $9,882. By 2014-15, that number exploded to $26,740.

For public universities, the tuition figures went from $2,196 to $8,534.

There isn't a consensus on the single reason college tuition has exploded in the past three decades. Colleges, like all organizations, aren't a monolith. Still, a few discussions recur about the reason for exploding college tuition.

Paul Aker was arrested after he failed to appear in court over repayment of a $1,500 student loan he received in 1987. screengrab via Fox One explanation for the trend is that students, rather than state governments, are absorbing more of the costs of college.

Budgetary cuts to higher education happened en masse around the US following the recession in 2007 when state tax revenues fell drastically.

But as the economy has clawed its way back to pre-recession numbers, college spending has stagnated or been cut.This puts the burden of rising tuition costs on students and families. As a result, state colleges and universities have even cut staff and eliminated programs.

A paper from the Federal Reserve Bank of New York also suggested that the government was to blame for colleges raising their sticker prices because the federal government was giving students more loans. As students became able to borrow more money, colleges, in turn, increased their tuition costs, the paper stated.

Regardless of the specific reason for tuition increases, the stakes for student borrowers are incredibly high.

Unlike consumer debt, it's extremely unlikely to have student loan debt discharged, even in cases of bankruptcy, meaning the government can follow you around your entire life until the debt is paid off.

Notably, seven US Marshalls arrested a man in February after he failed to appear in court over repayment of a $1,500 student loan he received in 1987.