Bulgaria's economy shrank by a real four per cent year-on-year in the first quarter of 2009, the country's National Statistics Institute (NSI) said in a flash estimate on May 12.In absolute terms, first-quarter gross domestic product (GDP) was 13.98 billion leva, NSI said in a statement.The decline was higher than expected by a panel of seven analysts polled by Bloomberg and quoted by Dnevnik daily. Their forecast was that Bulgaria's economy would shrink by three per cent in the first quarter.The agriculture sector posted the highest drop, 3.4 per cent year-on-year, while the services and industrial sectors declined by 2.2 per cent and 1.3 per cent, respectively.Consumption, which was one of the main drivers of economic growth in recent years, was down an annual 6.8 per cent for the quarter and investment was 15.8 per cent lower. Despite an increase in exports and continued decline of exports, the trade gap for the first quarter was expected to be 8.7 per cent of GDP.NSI's flash estimates, which were launched in 2008, are based on limited data and are subject to revision. The statistics board is scheduled to publish detailed data for the first quarter of 2010 on June 9.