RMR's business primarily consists of providing management services to four publicly owned real estate investment trusts, or REITs, and three real estate operating companies. As of March 31, 2016, RMR had $22.0 billion of real estate assets under management, including more than 1,300 properties. The RMR Group manages Hospitality Properties Trust (HPT), a publicly traded REIT that owns hotels and travel centers, Senior Housing Properties Trust (SNH), a publicly traded REIT that owns healthcare, senior living and medical office buildings, Government Properties Income Trust (GOV), a publicly traded REIT that primarily owns and leases office buildings that are majority leased to government tenants, and Select Income REIT (SIR), a publicly traded REIT that is focused on owning and investing in net leased, single tenant properties. RMR also provides management services to Five Star Quality Care, Inc., a senior living and healthcare services company which is a tenant of SNH and manages certain of SNH's senior living communities, to TravelCenters of America, LLC, an operator of travel centers which is a tenant of HPT, and to Sonesta International Hotels Corporation, which is one of HPT's hotel managers. Another subsidiary of RMR, RMR Advisors LLC, is an SEC registered investment advisor that is the investment manager of a publicly traded mutual fund which principally invests in securities of unaffiliated real estate companies. RMR is a member of the U.S. Green Building Council and an Energy Star Partner.