Please answer a question about the following article about Arnold Schwarzenegger:

Schwarzenegger's early victories included repealing an unpopular increase in the vehicle registration fee as well as preventing driver's licenses being given out to illegal immigrants, but later he began to feel the backlash when powerful state unions began to oppose his various initiatives. Key among his reckoning with political realities was a special election he called in November 2005, in which four ballot measures he sponsored were defeated. Schwarzenegger accepted personal responsibility for the defeats and vowed to continue to seek consensus for the people of California. He would later comment that "no one could win if the opposition raised 160 million dollars to defeat you". The U.S. Supreme Court later found the public employee unions' use of compulsory fundraising during the campaign had been illegal in Knox v. Service Employees International Union, Local 1000.

How many of Schwarzenegger's ballot initiatives were defeated in the special election of 2005?
four