The quadratic regression corresponding to the number of jogging strollers sold each year from 2007 to 2012, where x = 1 corresponds to year 2007, is f(x) =-2.9286x2 +20.243x + 36.4. Use the quadratic regression to project what future year the number of jogging strollers will equal 38. Round your answer to the nearest whole number. Do not include a comma in your answer. Provide your answer below: year