SRS tracking error

Voltron says: When I eyeball the chart of SRS versus the index it is supposed to track (IYR), it seems like SRS should be much higher. To put my mind at ease, I made a spreadsheet that calculates where SRS should be if it tracked the index perfectly since it's peak on Nov 20, 2008. It turns out not to be as bad as I thought . . . SRS should be about $11 higher (15%). The tracking error has been consistently negative and has been pretty stable around 15% since SRS went ex-dividend on Dec 23rd. If you reset and track the error since Dec 23rd, it swings positive and negative and is generally under 1%. Conclusion: SRS performs as advertised and errors are mostly due to anticipation of dividend payments which are required by tax law.

link to spreadsheet here