Calculating Changes between user defined periods

[spartan27244]

I need to create the rate of change between the periods in a slicer, below is an example visual.

You can see that the user has selected a range of report periods, and the dates in the grid are for illistrative purposes so you can see that we are not necessarily working with calendar years, but user selected/defined reports periods that are in a table related to the "Date" table which relates to the claims values, see model below.

Note that PMPMMedPlan is itself a measure that is calculated as "PMPMMedPlan = Sum('Med Claims'[MedPlanPaid]) / Sum(PME[MM])"

Considering

Plan Paid PMPM Rate Changes
Year	PMPM	Yr to Yr
2016f	$287.74
2017f	$311.32	7.5%
2018f	$348.03	10.5%
2019f	$345.07	-0.9%
2020f	$342.47	-0.4%

I need to calculate "Yr to Yr" which is the difference between periods) / value for current period i.e.

For 2020f    ((342.47 - 345.07) / 342.47) = -1.2 / 342.47 = -0.0035039565509388, to be expressed as % = -0.4%

[amitchandak]

@spartan27244 , usually in such cases when do have standard period we use rank on period

New column in date table

new column

Period Rank = RANKX(all('Period'),'Period'[year period],,ASC,Dense)

measure

This Period = CALCULATE(sum('order'[Qty]), FILTER(ALL('Period'),'Period'[Period Rank]=max('Period'[Period Rank])))
Last Period = CALCULATE(sum('order'[Qty]), FILTER(ALL('Period'),'Period'[Period Rank]=max('Period'[Period Rank])-1))

Last year same period= CALCULATE(sum('order'[Qty]), FILTER(ALL('Date'),'Date'[Year]=max('Date'[Year])-1 && 'Date'[Month] = Max('Date'[Month])))

or

Last Year Period = CALCULATE(sum('order'[Qty]), FILTER(ALL('Period'),'Period'[Period]=max('Period'[Period]) && 'Period'[Year]=max('Period'[Year])-1))

new column

Year Rank = RANKX(all('Date'),'Date'[Year Start date],,ASC,Dense)

new measures
This Year = CALCULATE(sum('order'[Qty]), FILTER(ALL('Date'),'Date'[Year Rank]=max('Date'[Year Rank])))
Last Year = CALCULATE(sum('order'[Qty]), FILTER(ALL('Date'),'Date'[Year Rank]=max('Date'[Year Rank])-1))

[spartan27244]

These are not standard Calendar year periods as indicated in the dates shown for illustrative purposes.  In addition the ReportPeriod table is a customer populationId, a Group Name (Calendar Year, Fiscal Year, Benefit Year, Custom), a period name 2015, 2016, 2017, etc. and a date field MedDate. There is a MedDate for every day within the period so that it redily joins with the model's DATE table.