The rate of bicycle fatalities in New York City increased 40 percent in 2005 from 2004 — 21 bicyclists died compared to 15 the year before."The increase in bicyclists killed last year is of great concern to us and we're working with the Police Department and advocacy groups to initiate a bicycle safety outreach campaign," said Transportation Department spokeswoman Kay Sarlin.She said New York City Health and Transportation departments are studying bike fatalities, hoping to better understand contributing factors, such as speeding and failure to wear helmets, the New York Daily News reported Friday.The increase in the fatalities may be due to the fact the an estimated 120,000 people cycle each day in New York — believed to be an all-time high, according to the group Transportation Alternatives.