1 Relative frequency: the result of dividing the absolute frequency of a certain value by the total number of data.  The sum of the relative frequencies is equal to $$1$$. We can prove this easily by factorizing $$N$$. Cumulative frequency: the sum of absolute frequencies of all the values equal to or less than the considered value.
Having said that you should have to wait 8 years from the last FILING DATE of your previous bankruptcy. The old time period prior to 2005 was 7 years before you could file again, but that was expanded to 8 years after the Bankruptcy Abuse and Consumer Protection Act of 2005 was passed.
When filing a Chapter 13 bankruptcy, the court must approve your payment plan. If it denies your plan, and this is your second filing for Chapter 13, then you will likely have to file a Chapter 7. The timeline of waiting six years will apply.