We are a nonprofit that is reorganizing our budgeting for 2019 (we operate on a calendar year) to better match our actual programming. As part of that, we would like to rename some classes in Quickbooks and also change their structure (i.e., move some classes to sub-classes). We know how to make those changes but what we don't know is what happens to all of the data then. Are all of the records from previous years now converted to that new structure, or do the changes just apply going forward? If the former, it seems strange to change classes for years that are closed and audited. If the latter, how can we then run YTD P&L comparison reports with previous years? We are running Quickbooks 2016 Premier for Nonprofits (desktop).