try this:

http://www.consolidatedtravel.com.au/qf/taxes.asp

choose either By Country or By Airline

For US:

YC ARRIVAL CUSTOMS FEE

INT ARR
ALL PAX NO EXEMPTIONS
Exemptions
NOT EX CANADA/MEXICO
5.00 USD


XA ANIMAL AND PLANT HEALTH INSPECTION SERVICE FEE

INT ARR
PLS REFER FFA FOR MORE DTLS
Exemptions
NOT EX CANADA
3.00 USD


XY IMMIGRATION INSPECTION FEE

INT ARR
ALL PAX NO EXCEMPTIONS
Exemptions

6.00 USD

AY FEDERAL SECURITY TAX

EACH DEPT
FOR 4 ENPLANEMENTS PER ROUND TRIP OR A MAXIMUM OF US10.00
Exemptions
PLEASE REFER TO CRS

YQ is usually an airline surcharge. Q is another airline one I am guessing. Which airline is this with?