Solid hiring helped lower unemployment rates in 40 of the 50 U.S. states in April, the most since November, the government reported Friday. The declines in jobless rates show labor markets are improving in most areas of the country. The Labor Department said unemployment rates rose only in three states-Louisiana, Tennessee, and North Dakota-and were unchanged in seven states. California, New York, and South Carolina reported the biggest declines in April unemployment. Each state's rate fell by 0.4 percentage point. Nationally, employers added 165,000 jobs in April, and the unemployment rate fell to a four-year low of 7.5 percent. The economy has added an average of 208,000 jobs each month since November, up from only 138,000 a month in the previous six months.