Statistics measuring city government performance are now available online, Mayor Bloomberg announced yesterday.

A new database, known as the Citywide Performance Reporting system, tracks some 300 statistics relating to agency operations in public safety, education, the economy, and other categories, mostly will be updated monthly.

The new system offers “sharper, clearer accountability than city government has ever had before,” the mayor said.

The online database, which New Yorkers can view at nyc.gov, is an offshoot of the Mayor’s Management Report, an annual evaluation of city agencies that measures 1,000 performance indicators, from grade school test scores to the average time it takes to fix a pothole. Yesterday, the mayor released a preliminary version of the report examining the first four months of fiscal year 2008, which ended October 31, 2007.

According to the new data, crime continues to fall to record lows. Murders declined 18%, to 170 between July and October 2007, from 207 during the same period in 2006, while major felonies dropped 5% overall.

Noise complaints increased by nearly a third, to 19,998 between July and October 2007, compared to 15,076 in the same period in 2006. Health statistics were mixed for city residents: Syphilis cases, which have been climbing across the country, rose sharply in the city, up 56% from 2006, while lead poisoning cases among children declined by 17%.

The office of the chief medical examiner reported a dramatic change in the average time required to complete an autopsy, down more than half, to 51 days in 2007 from 106.5 days in 2006. The report attributed the difference to better supplies and procedures for toxicology testing.