You cannot enter expressions as criteria in "stored" finds like this.
Do it this way. It will work and is also much easier to read when you need to work with your script in the future:
Enter Find Mode 
Set Field [Caroling Signup::Years Attended ; Year ( Get ( CurrentDate ) ) ]
Set Error Capture [on] // suppresses "no records found" dialog so that it can't interrupt your script
You can also assign Year ( Get ( CurrentDate ) ) to a variable and refer to the variable in your stored find request if you have FileMaker 11, but I perfer the above approach as I can see what is being specified for my find criteria without having to click a button to bring up another window to see it.
I am new to the use of variables. How might I do it that way?
it only works with FileMaker 11.
Set Variable [$year ; Value: Year ( Get ( CurrentDate ) )]
Then you can specify $Year in your stored find criteria.
Awesome! Problem solved. Thank you.