The first 2 digits of the serial number are the Date code, so by using the chart below you can tell exactly when your machine came of the production line.( As opposed to when the store sold it.) Therefore the example serial number of 23290056 shows the machine came of the production line in November 2003.
As you can see every ninth year the numbers recycle which means your appliance could have been made in either of the years listed, however there were only a few models made that cover the eight year time span so you are reasonably safe to assume the date code on your appliance will fall within the boundaries listed.