Understand the NAV Method
The minimum NAV method is backwards compatible (that is, this option does not change the returns you were calculating with previous versions).
To use this calculation method, select the Begin NAV method option when you set up a Dynamic Mutual Fund Returns field. The Minimum NAV method is the default. If you edit a Dynamic Mutual Fund Returns field that was created using a prior version, the option remains defaulted to use the Minimum NAV method unless you change it. 
Here is an example of how the CDSC Load Method option works:
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