Linking Two Tables to Calculate using Expression Builder

[gr9684_2017]

Hello I have two tables. Table 1 shows the sum of employment (sumemp) by region quarterly (1581 records). Table 2 shows is the same as the last table by it is disaggregated by industry (32,300 records)
I need to create expression to calculate location quotient as employment from table 2/employmentt total table 1.
How do I link the two tables in a query? When I am done I should have location quotient for 32,300 records. Thanks for the insights!!

PS I attached text files and I did not provide the full version of table 2.

[June7]

The datasets can be linked on MSA, Year, Quarter. Then do whatever calcs you want with the two SumOfEmp fields.

Year is a reserved word and should not use reserved words as names for anything.

[gr9684_2017]

Thank you for your advice! Question: When I created the query, I will need to join properties. In which direction should join property be linked? I tried this already and still getting bizarre output.