MAXIFS formula that excludes based on date

I am trying to write a maxifs statement that will give me the greatest number for a person but only where the start date year of their number is less than 2020.
So in the case, the maxifs formula should identify the number for Person1 to be 15, not 20. My current formula is MAXIFS(B:B,A:A,A1), which pulls in 20. I do not know how to tell the formula to ignore the row with the year 2020.

Column A Column B Column C
Person1 20 1/15/2020
Person1 15 8/3/2019
Person1 10 7/2/2017
Person1 5 5/5/2015
Person1 5 3/1/2011

Try this

=AGGREGATE(14,6,$B$2:$B$6/(YEAR($C$2:$C$6)< 2020),1)