Question: When was smoking banned in restaurants in the state where Detroit's largest employer is located?

<P0-S0> within the city of detroit, there are over a dozen major hospitals which include the detroit medical center (dmc), henry ford health system, st. john health system, and the john d. dingell va medical center. <P0-S1> the dmc, a regional level i trauma center, consists of detroit receiving hospital and university health center, children's hospital of michigan, harper university hospital, hutzel women's hospital, kresge eye institute, rehabilitation institute of michigan, sinai-grace hospital, and the karmanos cancer institute. <P0-S2> the dmc has more than 2,000 licensed beds and 3,000 affiliated physicians. <P0-S3> it is the largest private employer in the city of detroit. <P0-S4> the center is staffed by physicians from the wayne state university school of medicine, the largest single-campus medical school in the united states, and the united states' fourth largest medical school overall. <SEP> <P1-S0> DMC Rehabilitation Institute of Michigan (RIM) is one of the eight hospitals affiliated with the Detroit Medical Center. <P1-S1> RIM is one of the largest, academic, rehabilitation hospitals in the United States specializing in rehabilitation medicine and research. <P1-S2> RIM offers clinical treatment in spinal cord injury, brain injury, stroke, complex trauma and orthopedics and catastrophic injury care. <P1-S3> The Institute is home to the Center for Spinal Cord Injury Recovery, a facility designed to implement and study innovative treatments in spinal cord injury recovery. <SEP> <P2-S0> Thousands more employees work in Midtown, north of the central business district. <P2-S1> Midtown is also home to watchmaker Shinola and an array of small and/or startup companies. <P2-S2> Midtown's anchors are the city's largest single employer Detroit Medical Center, Wayne State University, and the Henry Ford Health System in New Center. <P2-S3> New Center bases TechTown, a research and business incubator hub that’s part of the WSU system. <P2-S4> Like downtown and Corktown, Midtown also has a fast-growing retailing and restaurant scene. <SEP> <P3-S0> founded in 1829 on an isthmus between lake monona and lake mendota, madison was named the capital of the wisconsin territory in 1836 and became the capital of the state of wisconsin when it was admitted to the union in 1848. that same year, the university of wisconsin was founded in madison and the state government and university have become the city's two largest employers. <P3-S1> the city is also known for its lakes, restaurants, and extensive network of parks and bike trails, with much of the park system designed by landscape architect john nolen. <SEP> <P4-S0> Statewide smoking ban: On May 1, 2010, after being signed into law by Governor Jennifer Granholm on December 18, 2009, the Dr. Ron Davis Law took effect, banning smoking statewide in all enclosed, indoor workplaces in Michigan, as well as the outdoor patios of bars and restaurants. <P4-S1> The law exempts only cigar bars, retail tobacco stores, private home offices, company vehicles including commercial trucks, and Detroit's three casinos' gambling floors. <P4-S2> The law is silent as to whether local governments may regulate smoking more strictly than the state, though it prohibits state or local health departments from enacting any smoking rules different than the law. <P4-S3> In December 2011, a judge dismissed fines against a Warren, Michigan bar owner who had claimed that his bar's Keno machines classified his establishment as a casino exempt from the ban.