Software Bills of Materials (SBOMs) are essential to ensure the transparency and integrity of the software supply chain. There is a growing body of work that investigates the accuracy of SBOM generation tools and the challenges for producing complete SBOMs. Yet, there is little knowledge about how developers distribute SBOMs. In this work, we mine SBOMs from Maven Central to assess the extent to which developers publish SBOMs along with the artifacts. We develop our work on top of the Goblin framework, which consists of a Maven Central dependency graph and a Weaver that allows augmenting the dependency graph with additional data. For this study, we selected a sample of 10% of release nodes from the Maven Central dependency graph and collected 14,071 SBOMs from 7,290 package releases in Maven Central. We then augmented the Maven Central dependency graph with the collected SBOMs. We present our methodology to mine SBOMs, as well as novel insights about SBOM publication. Our dataset is the first set of SBOMs collected from a package registry, and we make it available as a standalone dataset, which can be used for future research about SBOMs and package distribution.