In @RISK risk modeling software, you can correlate a time series that has a similar set of input distributions in each time period. You just tell @RISK which variables in your risk analysis model to correlate in each time period. @RISK automatically creates a correlation instance – a copy of the same correlation matrix for a new set of inputs – for each period in the time series. This saves you a lot of time. You can then make adjustments to each year as needed.
Here’s a quick video showing how to do this: