According to the recent LA Times article dated July 27, 2017; the percentage of paroles approved in California has been on the rise between 1985 and 2014. In 1985, early release recommendations by the parole board were 7.8% with less than 2,000 parole hearings. In 2014, a little over 5,000 parole hearings were conducted and nearly 20% of the cases heard were approved for parole.
More discretion has been given to the State parole board to recommend early release due to new laws. In 2008 for example, the California Supreme Court held that inmates could not be denied based solely on the severity of the crime committed, instead, if released, a determination of whether the defendant would pose a safety risk to the public should be analyzed.
Themarshallproject.org article dated November 27, 2017 will explain... "A little more than a year after the passage of Prop. 64, at least 2,660 petitions have been filed to reduce sentences for people convicted of pot-related offenses."