The economy is set to witness a roller-coaster growth in the next three years ranging between 6-7% mainly due to fluctuations in the prospects of industry and services, according to Asian Development Bank (ADB).In the Asian Development Outlook released today, ADB said growth is expected to be marginally higher at 6.9% in 2005, which would fall to 6.1% in 2006 only to bounce back to 7% in 2007.The Manila-based multilateral lending agency expects farm sector to grow by a healthy 4.4% in 2005 even as industrial sector is expected to decelerate to 6.7% while services sector is set to witness 7.7% growth.ADB said the industrial slowdown in 2005 would be mainly due to "cost smoothing" behaviour of firms to tide over the expected cost escalation as reflected in the latest business confidence survey of NCAER.In 2006, it said GDP growth is expected to decline to 6.1% due to further deceleration in the growth of industry and services to 5.2% and 7.3%, respectively."The revival of industrial and services growth in 2007 will drive up overall expansion to 7%," ADB said.