Also added the QBO model to the spreadsheet. Essentially the same model fitting algorithm is used for both ENSO and QBO, but using a different set of forcing functions. For ENSO, the draconic and anomalistic tide is modulated with a biennial signal, while QBO modulates only the draconic with an annual signal.

![qbo](http://imageshack.com/a/img923/8453/z8RdQL.png)