Brace for growth numbers starting with "6" from China this year, economists say, after data showed the world's second largest economy expanded at its slowest pace in over two decades in 2014.

China's gross domestic product (GDP) release on Tuesday showed the economy grew 7.3 percent in the fourth quarter from the year-ago period, bringing growth in the full year to 7.4 percent – the weakest performance since 1990.