Gravity Measurement

[Meab5]

Hello In my physics class we have just completed a lab on measuring the acceleration due to gravity. For my analysis I wanted to include that there was a percent error because the accepted value is not necessarilly the actual value for my city. Does anyone know where I can find the actual value for acceleration due to Gravity for my city.
Any help would be apreciated
Thanks

[jamesrc]

This should help you estimate it:

http://www.mines.edu/fs_home/tboyd/GP311/MODULES/GRAV/NOTES/latitude.html