Marketo Inactive User List Filters

I want to extract a list of contacts that have been inactive since 2017. What are the filters required in the Smart List for capturing the accurate data? I am currently using the below filters. However, on extracting the data the Last Activity Date is blank. Also, what is the difference between Last Viewed Date and Last Viewed Date (A). Am i using the correct filters? Do let me know in case of any other filters that need to be added.

Regards,

Ashwyn Rao