| Year | Internal flow (million m3) | Inflow of surface and groundwater from neighbouring countries (million m3) |
|---|---|---|
| 2000 | 9246.5 | 27445.9 |
| 2001 | 9115.3 | 27179.2 |
| 2002 | 13039.2 | 30874.3 |
| 2003 | 14137.6 | 32744.5 |
| 2004 | 13247.4 | 31228.8 |
| 2005 | 9824.4 | 28238.6 |
| 2006 | 11177.1 | 33359.9 |
| 2007 | 12044.8 | 30057.9 |
| 2008 | 10264.5 | 25358.9 |
| 2009 | 12401 | 25478.4 |
| 2010 | 10640 | 31805.4 |
| 2011 | 12299 | 28935.4 |
| 2012 | 10907 | 24237.4 |
| 2013 | 10031 | 23011.4 |
| 2014 | 9684 | 22639.4 |
| 2015 | 7985 | 22889.4 |
| 2016 | 10792 | 23526.4 |
| 2017 | 8612 | 20811.4 |