Experiment	Measurement	Reference
BaBar	\([2.16 \pm 0.52\mbox{ (stat)} \pm 0.45\mbox{ (syst)}] \times 10^{-4}\)	PRD 77 011102 (2008)
Average	\(\mathbf{[2.16 \pm 0.69\mbox{ (combined)}] \times 10^{-4}}\)