How to count specific words in multiple PDFs and it should be presented in a table using R

Question

I have multiple PDFs. I want to create a table where the frequency of specific keywords are counted and tabulated. I want the output to look like this;

Company name.  Year   ID.   Keyword count
Colgate        2011    1       5  
Colgate        2012    1       0  
Colgate        2013    1       6
Colgate        2014    1       5  
Pfizer         2011    2       3  
Pfizer         2012    2       2  
Pfizer         2013    2       1

I applied the following code but it doesn't count the keywords.

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