Pareto Chart by Period

[Anonymous]

I have 5yrs of historical data where I need to provide a chart that tells me how many 'Customers' contributed to the Top 80% of sales

I have managed to get this far by using RANKX (Refer image)

Issues

1) I dont know how to write a DAX that only COUNT the number of customers giving me Top 80% of Sales (highlighted in Green in the image). I dont want to use to use the FILTER pane

2) I dont know how to write a DAX to help me provide below (including a bar chart)

	FY16	FY17	FY18	FY19	FY20
No. Customers contributing to Top80% of Sales	100	85	95	110	115

[Anonymous]

1RANK = RANKX(ALL(lookupPartner[Partner Id w Name]),[Actuals Historical],,DESC)

Actuals Historical Cumulative = CALCULATE([Actuals Historical],TOPN([1RANK],ALLSELECTED(lookupPartner[Partner Id w Name]),[Actuals Historical]))

Actuals Historical Cumulative % = DIVIDE([Actuals Historical Cumulative], [Actuals Historical (partnerID all selected)])