Expression to find last year - not working

Hello,

I'm preparing a report which, when ran in January, will display "December 2018" with an expression. While the "December" part works, running it keeps displaying the current year instead of the previous one. 

This is the expressions I came up with:

=IIF(Today.Month>1,MonthName(Month(DateAdd("M",-1,CDate(Today))))& " "& (Year(DateAdd("Y",0,CDate(Today)))),MonthName(Month(DateAdd("M",-1,CDate(Today))))& " "& (Year(DateAdd("Y",-1,CDate(Today)))))

It's probably a simple mistake somewhere but I can't find it:/

Many thanks in advance for your help.

Regards,

Wojciech