| Year | Volume (ton) | Price (1,000 dollar) |
|---|---|---|
| 2012 | 468,586 | 150,143 |
| 2013 | 405,421 | 144,487 |
| 2014 | 653,394 | 196,069 |
| 2015 | 667,547 | 160,250 |
| 2016 | 862,498 | 184,708 |
| 2017 | 945,113 | 174,051 |
| 2018 | 1,096,294 | 245,331 |
| 2019 | 1,147,287 | 250,912 |
| 2020 | 1,127,894 | 250,632 |
| 2021 | 1,044,356 | 313,208 |
| 2022 | 1,134,022 | 392,120 |
| 2023 | 1,120,178 | 369,635 |