That is easy.
Since the deer are managed by unit instead of with those statewide results the improvements that were needed are being realized within the units where it was most needed. That is why in areas like this area both the breeding rates and window have been so greatly improved over the past half dozen years.
Some units though do seem to be experiencing some slight declines, most likely due to having populations that have grown out of the balance of the habitat. Those various habitat/deer density issues and problem areas will be addressed, on a unit by unit bases, with various management options in the future.
Unfortunately for you the answer is not at all easy. If breeding rates improved significantly in the WMUs with the poorest breeding rates, but the state wide average still decreased by 5% that means an equal number of WMUs had decreases in breeding rates that were double the amount of the increase in the WMUs where breeding rates improved. For example, if breeding rates improved by 10% in 2G the breeding rates would have to decrease by 10% in another WMU with a similar sample size. But in order to get a 5% average decrease the breeding rate in one WMU would have to decrease by 20%
You had a hard time admitting statewide breeding rates decreased by 5% so how are you going to explain decreases of 20% in the WMUs which previously had higher breeding rates? The answer is you can't and the only logical explanation for the 5% decreased is that breeding rates declined in the vast majority of the WMUs.