Experiment	Measurement	Reference
Belle	\([2.75 \pm 0.62\mbox{ (stat)} \pm 0.36\mbox{ (syst)}] \times 10^{-4}\)	PRD 83, 051102(R) (2011)
Average	\(\mathbf{[2.75 \pm 0.72\mbox{ (combined)}] \times 10^{-4}}\)