China's economy grew 6.9 percent year on year in 2015, the slowest annual expansion in a quarter of a century, but it is still in line with the official target, according to data from the National Bureau of Statistics (NBS) on Tuesday.

Growth in the fourth quarter came in at 6.8 percent year on year, the lowest quarterly rate since the global financial crisis, the data showed.

The Chinese government targeted an annual economic growth of around 7 percent for 2015.

The country's gross domestic product (GDP) reached 67.67 trillion yuan (about 10.3 trillion US dollars) in 2015, with the service sector accounting for 50.5 percent, the first time the ratio exceeded 50 percent, according to the NBS.

China's economy still "ran within a reasonable range" in 2015, with its structure further optimized, upgrading accelerated, new growth drivers strengthened and people's lives improved, NBS chief Wang Baoan told a press conference.

However, the country faces a daunting task in deepening reforms on all fronts and needs to step up supply-side structural reforms, he said.

Major economic indicators softened in 2015, with industrial output growth slowing to 6.1 percent year on year from 8.3 percent in 2014, NBS figures showed.

Urban fixed-asset investment continued to cool, expanding 10 percent year on year, compared with 15.7 percent in 2014. Retail sales rose 10.7 percent, down from 12 percent registered in 2014. Foreign trade ended 2015 with its first annual contraction in six years.

Sagging global trade, rising financial risks and changing domestic market conditions were among the factors affecting the economy, Wang said.

He also pointed to an ailing property sector and stock market fluctuations but said their impact on the economy was either limited or yet to be evaluated.

Wang dismissed worries about China's government debts, noting that they accounted for less than 40 percent of the country's GDP, well below the internationally accepted alert line of 60 percent.

BRIGHT SIDE

Viewed against an international backdrop, a 6.9 percent growth was "not a low rate" and outshined other global economies, Wang said, defending it as a hard-won achievement.

Though slowing, China still contributed more than 25 percent of the global economic growth, he said.

Employment remained stable, with the surveyed unemployment rate in major cities standing around 5.1 percent. Income also continued to increase steadily, Wang noted.

While old engines in China's economy -- investment and trade -- lost steam, services and consumption took the reins.

End-user consumption, including resident and government spending, contributed 66.4 percent of the national GDP growth in 2015, up 15.4 percentage points from 2014, the NBS data showed.

While expecting some sectors to weaken further this year as authorities advance reforms to cut overcapacity and reduce costs, Wang was confident that China could attain a steady growth in 2016, pointing to thriving emerging industries and new business models.

Online retail sales of goods surged 31.6 percent in 2015, well above the total retail sale growth, he told reporters. Sales of new energy vehicles soared by more than 160 percent, while the output growth for the high-tech industry reached 10.2 percent, 4.1 percentage points higher than the overall industrial output.

China's efforts to make the economy greener and more productive also sank in, with energy consumption per unit of GDP falling 5.6 percent and overall labor productivity, measured by output per worker, rising 4,733 yuan last year, Wang said.