Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Year | Denomination | Reverse | Weight | Diameter | Fineness | Series |
| --- | --- | --- | --- | --- | --- | --- |
| 2006.0 | 150 Yuan | Equestrian | .33 Troy Ounce | 23mm | .9999 Gold | I series |
| 2006.0 | 150 Yuan | Archery | .33 Troy Ounce | 23mm | .9999 Gold | I series |
| 2007.0 | 150 Yuan | Weightlifting | .33 Troy Ounce | 23mm | .9999 Gold | II series |
| 2007.0 | 150 Yuan | Swimming | .33 Troy Ounce | 23mm | .9999 Gold | II series |
| 2008.0 | 150 Yuan | Chinese Cuju Sport | .33 Troy Ounce | 23mm | .9999 Gold | III series |
| 2008.0 | 150 Yuan | Wrestling | .33 Troy Ounce | 23mm | .9999 Gold | III series |
Question:
What's the diameter of the 2006 equestrian Reverse?
Answer:
23mm