| Share | Phrase |
|---|
| 19.52% | process [does] upgrade |
| 18.67% | upgrade feedstock [perform operation] |
| 16.46% | upgrade oil [perform operation] |
| 8.25% | upgrade gasoline [perform operation] |
| 7.31% | upgrade fuel [perform operation] |
| 7.17% | upgrade system [perform operation] |
| 7.10% | relate for upgrade |
| 6.36% | upgrade number [perform operation] |
| 5.25% | provide for upgrade |
| 3.86% | upgrade modal can |