| Report Date | Amount Outstanding (Billions) |
|---|---|
| December 31, 2011 | $328 |
| December 31, 2012 | $334 |
| December 31, 2013 | $406 |
| December 31, 2014 | $464 |
| December 31, 2015 | $495 |
| December 31, 2016 | $563 |
| December 31, 2017 | $583 |
| December 31, 2018 | $573 |
| December 31, 2019 | $482 |
| March 31, 2020 | $613 |
Last Updated: February 3, 2022