Customer retention new vs old Customers

I want to calculate yearly retension report for the follwing data.

1. I like to find how many old customers from 2017 are with us in 2018
2. Also number of new customers in 2018.

Plz help. I am a newbie and need to generate this report for the management.

I like to find how many old customers from 2017 are with us in 2018

 Measure =
COUNTROWS(INTERSECT(SELECTCOLUMNS(FILTER(table1,year(Table1[year])=2017),"2017_yr_nm",Table1[name]),
SELECTCOLUMNS(FILTER(table1,year(Table1[year])=2018),"2018_yr_nm",Table1[name])))
Also number of new customers in 2018.
 Measure = 
COUNTROWS(except(SELECTCOLUMNS(FILTER(table1,year(Table1[year])=2017),"2017_yr_nm",Table1[name]), 
SELECTCOLUMNS(FILTER(table1,year(Table1[year])=2018),"2018_yr_nm",Table1[name]))) 
 

Hi function to find Retension of customers from last year is working perfectly. But 2nd equation for finding new customers is returning a wrong value. Can you plz look into this for me??

I think i found the solution. Hope it is useful to everyone. I have created a parameter for year which you can swap for months or years based on adding a calender to solution.

Here is the link.

Check this