The big surprise in China’s economic growth data is how regularly it surprises economists, and typically it’s by the slimmest of margins.

The magic number seems to be 0.1 per cent, with the median estimate for quarterly GDP missing the mark by that magnitude in 10 of the past 16 quarters.

Thursday’s report delivered fourth-quarter expansion of 6.8 per cent — 0.1 percentage point faster than the projection in Bloomberg’s survey of 49 economists. Of those, 29 forecast 6.7-per-cent growth while 14 nailed the actual number.

Delving deeper, over the past four years economists have been too pessimistic a majority of the time. Just once — in the final quarter of 2015 — have they been overly optimistic, according to data compiled by Bloomberg.

Here’s how the past eight quarters compared with estimates:
 

Period Survey Actual Miss
2014 1Q 7.30% 7.40% 0.1%
2014 2Q 7.40% 7.50% 0.1%
2014 3Q 7.20% 7.30% 0.1%
2014 4Q 7.20% 7.30% 0.1%
2015 1Q 7.00% 7.00% 0.0%
2015 2Q 6.80% 7.00% 0.2%
2015 3Q 6.80% 6.90% 0.1%
2015 4Q 6.90% 6.80% -0.1%
2016 1Q 6.70% 6.70% 0.0%
2016 2Q 6.60% 6.70% 0.1%
2016 3Q 6.70% 6.70% 0.0%
2016 4Q 6.70% 6.80% 0.1%
2017 1Q 6.80% 6.90% 0.1%
2017 2Q 6.80% 6.90% 0.1%
2017 3Q 6.80% 6.80% 0.0%
2017 4Q 6.70% 6.80% 0.1%

The trend is intact in data since Bloomberg began regular surveys on Chinese expansion more than a decade ago. Quarterly growth topped estimates 56 per cent of the time in the past 12 years, while it fell short of expectations just 21 per cent of the time.