61, 61A and 61B very much are values. They are types and should go into your table as such. This is what that table should look like:
tblPropertyTaxClassification
ptc_ID, autonumber, primary key
ID_Property, number, foreign key to tblOwnderProperties.PropertyID
ptc_FiscalYear, number, fiscal year value
ptc_Classification, ?, will hold whatever Classification now holds
ptc_Acres, number, will hold number of acres
ptc_Type, text, will hold the type values of 61, 61A, 61B
Then instead of 3 fields for the 61, 61A, 61B data, you will have 3 records (one for each type, assuming they have a value for that type).