  In the last two decades, several researchers provided snapshots of the
"current" state and evolution of empirical research in requirements engineering
(RE) through literature reviews. However, these literature reviews were not
sustainable, as none built on or updated previous works due to the
unavailability of the extracted and analyzed data. KG-EmpiRE is a Knowledge
Graph (KG) of empirical research in RE based on scientific data extracted from
currently 680 papers published in the IEEE International Requirements
Engineering Conference (1994-2022). KG-EmpiRE is maintained in the Open
Research Knowledge Graph (ORKG), making all data openly and long-term available
according to the FAIR data principles. Our long-term goal is to constantly
maintain KG-EmpiRE with the research community to synthesize a comprehensive,
up-to-date, and long-term available overview of the state and evolution of
empirical research in RE. Besides KG-EmpiRE, we provide its analysis with all
supplementary materials in a repository. This repository contains all files
with instructions for replicating and (re-)using the analysis locally or via
executable environments and for repeating the research approach. Since its
first release based on 199 papers (2014-2022), KG-EmpiRE and its analysis have
been updated twice, currently covering over 650 papers. KG-EmpiRE and its
analysis demonstrate how innovative infrastructures, such as the ORKG, can be
leveraged to make data from literature reviews FAIR, openly available, and
maintainable for the research community in the long term. In this way, we can
enable replicable, (re-)usable, and thus sustainable literature reviews to
ensure the quality, reliability, and timeliness of their research results.
