Question: How many tornadoes occur per year in the state where its Civil War governor died?

full_context: Document 1: North Carolina: Severe weather occurs regularly in North Carolina. On the average, a hurricane hits the state once a decade. Destructive hurricanes that have struck the state include Hurricane Fran, Hurricane Floyd, and Hurricane Hazel, the strongest storm to make landfall in the state, as a Category 4 in 1954. Hurricane Isabel stands out as the most damaging of the 21st century. Tropical storms arrive every 3 or 4 years. In addition, many hurricanes and tropical storms graze the state. In some years, several hurricanes or tropical storms can directly strike the state or brush across the coastal areas. Only Florida and Louisiana are hit by hurricanes more often. Although many people believe that hurricanes menace only coastal areas, the rare hurricane which moves inland quickly enough can cause severe damage; for example, in 1989, Hurricane Hugo caused heavy damage in Charlotte and even as far inland as the Blue Ridge Mountains in the northwestern part of the state. On the average, North Carolina has 50 days of thunderstorm activity per year, with some storms becoming severe enough to produce hail, flash floods, and damaging winds.
Document 2: Raleigh, North Carolina: After the Civil War began, Governor Zebulon Baird Vance ordered the construction of breastworks around the city as protection from Union troops. During General Sherman's Carolinas Campaign, Raleigh was captured by Union cavalry under the command of General Hugh Judson Kilpatrick on April 13, 1865. As the Confederate cavalry retreated west, the Union soldiers followed, leading to the nearby Battle of Morrisville. The city was spared significant destruction during the War, but due to the economic problems of the post-war period and Reconstruction, with a state economy based on agriculture, it grew little over the next several decades.
Document 3: Modern history: Northern leaders agreed that victory would require more than the end of fighting. Secession and Confederate nationalism had to be totally repudiated and all forms of slavery or quasi-slavery had to be eliminated. Lincoln proved effective in mobilizing support for the war goals, raising large armies and supplying them, avoiding foreign interference, and making the end of slavery a war goal. The Confederacy had a larger area than it could defend, and it failed to keep its ports open and its rivers clear. The North kept up the pressure as the South could barely feed and clothe its soldiers. Its soldiers, especially those in the East under the command of General Robert E. Lee proved highly resourceful until they finally were overwhelmed by Generals Ulysses S. Grant and William T. Sherman in 1864–65, The Reconstruction Era (1863–77) began with the Emancipation proclamation in 1863, and included freedom, full citizenship and the vote for the Southern blacks. It was followed by a reaction that left the blacks in a second class status legally, politically, socially and economically until the 1960s.
Document 4: Raleigh, North Carolina: Raleigh is an early example in the United States of a planned city, chosen as the site of the state capital in 1788 and incorporated in 1792 as such. The city was originally laid out in a grid pattern with the North Carolina State Capitol in Union Square at the center. In the United States Civil War the city was spared from any significant battle, only falling in the closing days of the war, though it did not escape the economic hardships that plagued the rest of the American South during the Reconstruction Era. The twentieth century saw the opening of the Research Triangle Park in 1959, and with the jobs it created the region and city saw a large influx of population, making it one of the fastest growing communities in the United States by the early 21st century.
Document 5: North Carolina: As in the rest of the former Confederacy, North Carolina had become a one-party state, dominated by the Democratic Party. Impoverished by the Civil War, the state continued with an economy based on tobacco, cotton and agriculture. Towns and cities remained few in the east. A major industrial base emerged in the late 19th century in the western counties of the Piedmont, based on cotton mills established at the fall line. Railroads were built to connect the new industrializing cities. The state was the site of the first successful controlled, powered and sustained heavier-than-air flight, by the Wright brothers, near Kitty Hawk on December 17, 1903. In the first half of the 20th century, many African Americans left the state to go North for better opportunities, in the Great Migration. Their departure changed the demographic characteristics of many areas.
Document 6: Tennessee: While the state is far enough from the coast to avoid any direct impact from a hurricane, the location of the state makes it likely to be impacted from the remnants of tropical cyclones which weaken over land and can cause significant rainfall, such as Tropical Storm Chris in 1982 and Hurricane Opal in 1995. The state averages around 50 days of thunderstorms per year, some of which can be severe with large hail and damaging winds. Tornadoes are possible throughout the state, with West and Middle Tennessee the most vulnerable. Occasionally, strong or violent tornadoes occur, such as the devastating April 2011 tornadoes that killed 20 people in North Georgia and Southeast Tennessee. On average, the state has 15 tornadoes per year. Tornadoes in Tennessee can be severe, and Tennessee leads the nation in the percentage of total tornadoes which have fatalities. Winter storms are an occasional problem, such as the infamous Blizzard of 1993, although ice storms are a more likely occurrence. Fog is a persistent problem in parts of the state, especially in East Tennessee.
Document 7: Thomas Michael Holt: Col. Thomas Michael Holt (July 15, 1831 – April 11, 1896) was a prominent North Carolina industrialist who served as the 47th Governor of North Carolina from 1891 to 1893. Formerly a North Carolina State Senator and Speaker of the House of the North Carolina General Assembly, Holt was instrumental in the founding of North Carolina State University, as well as in establishing several railroads within the state and the state's department of agriculture. Holt was also responsible for the technology behind the family's Holt Mills 'Alamance Plaids,' the first colored cotton goods produced in the South – a development that revolutionized the Southern textile industry.
Document 8: Zebulon Baird Vance: Zebulon Baird Vance (May 13, 1830 – April 14, 1894) was a Confederate military officer in the American Civil War, the 37th and 43rd Governor of North Carolina, and U.S. Senator. A prolific writer, Vance became one of the most influential Southern leaders of the Civil War and postbellum periods. As a leader of the "New South", Vance favored the rapid modernization of the southern economy, railroad expansion, school construction, and reconciliation with the North.
Document 9: Vanceboro, North Carolina: Vanceboro is a town in Craven County, North Carolina, United States. The population was 1,005 at the 2010 Census. Originally called Swift Creek, residents renamed the town for Zebulon B. Vance after he made a visit during his 1876 campaign for Governor. It is part of the New Bern, North Carolina Micropolitan Statistical Area.
Document 10: Climate of North Carolina: There is an average of forty - five inches of rain a year (fifty in the mountains). July storms account for much of this precipitation. As much as 15% of the rainfall during the warm season in the Carolinas can be attributed to tropical cyclones. Mountains usually see some snow in the fall and winter. Moist winds from the southwest drop an average of 80 inches (2,000 mm) of precipitation on the western side of the mountains, while the northeast - facing slopes average less than half that amount.
Document 11: North Carolina: Confederate troops from all parts of North Carolina served in virtually all the major battles of the Army of Northern Virginia, the Confederacy's most famous army. The largest battle fought in North Carolina was at Bentonville, which was a futile attempt by Confederate General Joseph Johnston to slow Union General William Tecumseh Sherman's advance through the Carolinas in the spring of 1865. In April 1865, after losing the Battle of Morrisville, Johnston surrendered to Sherman at Bennett Place, in what is today Durham. North Carolina's port city of Wilmington was the last Confederate port to fall to the Union, in February 1865, after the Union won the nearby Second Battle of Fort Fisher, its major defense downriver.
Document 12: Charleston, South Carolina: After the defeat of the Confederacy, federal forces remained in Charleston during the city's reconstruction. The war had shattered the prosperity of the antebellum city. Freed slaves were faced with poverty and discrimination, but a large community of free people of color had been well-established in the city before the war and became the leaders of the postwar Republican Party and its legislators. Men who had been free people of color before the war comprised 26% of those elected to state and federal office in South Carolina from 1868 to 1876.
Document 13: Reconstruction era: As Confederate states came back under control of the U.S. Army, President Abraham Lincoln set up reconstructed governments in Tennessee, Arkansas, and Louisiana during the war. He experimented by giving land to blacks in South Carolina. By fall 1865, the new President Andrew Johnson declared the war goals of national unity and the ending of slavery achieved and reconstruction completed. Republicans in Congress, refusing to accept Johnson's lenient terms, rejected new members of Congress, some of whom had been high - ranking Confederate officials a few months before. Johnson broke with the Republicans after vetoing two key bills that supported the Freedmen's Bureau and provided federal civil rights to the freedmen. The 1866 Congressional elections turned on the issue of Reconstruction, producing a sweeping Republican victory in the North, and providing the Radical Republicans with sufficient control of Congress to override Johnson's vetoes and commence their own ``Radical Reconstruction ''in 1867. That same year, Congress removed civilian governments in the South, and placed the former Confederacy under the rule of the U.S. Army. The army conducted new elections in which the freed slaves could vote, while whites who had held leading positions under the Confederacy were temporarily denied the vote and were not permitted to run for office.
Document 14: Climate of North Carolina: Snow in North Carolina is seen on a regular basis in the mountains. North Carolina averages 5 inches (130 mm) of snow a year. However, this also varies greatly across the state. Along the coast, most areas register less than 2 inches (51 mm) per year while the state capital, Raleigh averages 7.5 inches (190 mm). Farther west in the Piedmont - Triad, the average grows to approximately 9 inches (230 mm). The Charlotte area averages approximately 6.5 inches (170 mm). The mountains in the west act as a barrier, preventing most snowstorms from entering the Piedmont. When snow does make it past the mountains, it is usually light and is seldom on the ground for more than two or three days. However, several storms have dropped 18 inches (460 mm) or more of snow within normally warm areas. The 1993 Storm of the Century that lasted from March 11 to March 15 affected locales from Canada to Central America, and brought a significant amount of snow to North Carolina. Newfound Gap received more than 36 inches (0.91 m) of snow with drifts more than 5 feet (1.5 m), while Mount Mitchell measured over 4 feet (1.2 m) of snow with drifts to 14 feet (4.3 m). Most of the northwestern part of the state received somewhere between 2 feet (0.61 m) an 3 feet (0.91 m) of snow.
Document 15: North Carolina: North Carolina averages fewer than 20 tornadoes per year, many of them produced by hurricanes or tropical storms along the coastal plain. Tornadoes from thunderstorms are a risk, especially in the eastern part of the state. The western Piedmont is often protected by the mountains, which tend to break up storms as they try to cross over; the storms will often re-form farther east. Also a weather phenomenon known as "cold air damming" often occurs in the northwestern part of the state, which can also weaken storms but can also lead to major ice events in winter.
ground_truth: fewer than 20
sub_queries: Who was the governor during the Civil War? Answer: Zebulon Baird Vance
In what city did Zebulon Baird Vance die? Answer: North Carolina
How many tornadoes does North Carolina have per year? Answer: fewer than 20