By what rule does the CBOE determine the available strikes for puts and calls on the SPX? The contract specification (http://www.cboe.com/products/stock-index-options-spx-rut-msci-ftse/s-p-500-index-options/s-p-500-options-with-a-m-settlement-spx/spx-options-specs) says
Strike Prices: In-,at- and out-of-the-money strike prices are initially listed. New series are generally added when the underlying trades through the highest or lowest strike price available.
Note that I am specifically not looking for traded options, but theoretically available options. I do have a dataset of option prices available, but options that have never been traded are not included.
Instead, I am looking for the initial minimum and maximum strike that CBOE makes available, and the added strikes that are created when the underlying trades through the initial bracket.