Rate window method for PersonalAutoCovCostData

The rateWindow method in PASysTableRatingEngine rates the following items.

• Multipolicy discounts
• Cancellation penalties
• Taxes

The multipolicy discount is notable because it rates essentially in slice mode, however just using the effective dates of the modifier itself. For each effective span, the discount sums the costs between that point in time and applies the discount to that period of time.

The cancellation penalty simply applies a flat percentage to the sum of all the costs computed up to that point in time (including the discount costs). Finally, tax calculations apply a percentage to the sum of all costs (including the cancellation penalty).