How to read all pdf files from a folder having pdf files of different formats

I have a scenario, where i need to read all the pdf files in a folder and write data to excel, that is manageable.

But there pdf files are of different formats.

Eg: Old Purchase Order doc are in different pdf format, PO’s after 2010 year are of different pdf formats, and also there are some other files too, which are in other pdf format

Note: Here the format means the arrangement of the tex/data

Please suggest