I see what you mean now. I've configured and enabled the index table engine for you, as I believe it's much better for your needs. To learn more about it, you can check the index table chapter in the documentation here: https://goo.gl/ooNYPY
It works better with your current keyword logic, as this also counts the word occurrence when calculating the relevance. It should return results most likely more relevant for what you might expect.
For future reference, what I did:
– Generated the index table on the index table submenu: https://i.imgur.com/LYub8ln.png
– After generation, selected the engine on the General Options -> Sources panel: https://i.imgur.com/XoYJQxo.png
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