What percent of your mortgage is paid down annually?

[Samuel Carmichael]

I heard on the Andrew Hines Real Estate Podcast that it was 3%. 

I just looked at my fourplex with a loan of $325,000, started the year at $329,500 so about $500 a month. 

But does anyone know what is standard loan paydown percentage annually?  

I hear it may be different from years 1-5, then from later in the amortization schedule.