| Year | Value (billion cubic meters per year) |
|---|---|
|
2020 |
1.82 |
|
2019 |
1.81 |
|
2018 |
1.81 |
|
2017 |
1.8 |
|
2016 |
1.8 |
|
2015 |
1.8 |
|
2014 |
1.8 |
|
2013 |
1.79 |
|
2012 |
1.79 |
|
2011 |
1.78 |