I have a project at school were we are supposed to find the generic series for US treasury bonds, and then download daily data for 3 years. I have found the bb ticker, but i don't understand the difference between regular and generic series? I have managed to download daily last price data for multiple maturities. After the data is downloaded, I am supposed to calculate the average return, either by yield to maturity or total return. This is were I'm stuck. I know how to calculate YTM, but am i really supposed to calculate the YTM for every single day (Prices changes) and then take the average of all of these YTMs? Is there something I'm missing? The problem set really doesn't specify what kind of data we are supposed to download for the series, but I couldn't find any thing called YTM when importing the data to excel. If I could do that, i presume that i could just have taken the average of all the YTMs.