Cal. Public Resources Code - PRC § 42496.4. Section 42496.4.
On July 1, 2007, and each July 1, thereafter, the department shall post on its Web site an estimated California recycling rate for cell phones, the numerator of which shall be the estimated number of cell phones returned for recycling in California during the previous calendar year, and the denominator of which is the number of cell phones estimated to be sold in this state during the previous calendar year.