Period over Period Changes

Hi 

I'm trying to get the sum unit year over year, the calculation is fine for 2018, 

However, for 2019 I just want the sum up to Feb 3rd actually,  but now the sum will up to end of Feb.
This make the Units YoY% very low at -46.4%

What should I do to get the Unit YoY% up to Feb 3rd?

Thanks in advance,

Simon