Question: How many tornadoes strike yearly on average in the state where the Hello Love performer lived when he died?

full_context: Document 1: Hank Snow: Snow moved to Nashville, Tennessee, in 1949, and "Hank Snow, the Singing Ranger" (modified from his earlier nickname, the Yodeling Ranger), began recording for RCA Victor in the United States in 1949. His first release in the United States, "Marriage Vow" climbed to number ten on the country charts in the fall of 1949; However, it wasn't until he was invited to play at the Grand Ole Opry in 1950 that he gained serious significance in the United States. His second release in early 1950, "I'm Moving On" was the first of seven number 1 hits on the country charts. "I'm Moving On" stayed at the top for 21 weeks, setting the all-time record for most weeks at number 1.
Document 2: Hello It's Me: ``Hello It's Me ''is a song composed, recorded, and performed by Todd Rundgren. Released as a single in September 1973, it reached no. 5 on the Billboard Hot 100 chart.
Document 3: Roy Orbison at the Rock House: According to the official Roy Orbison U.S. discography by Marcel Riesco, Roy Orbison at the Rock House is the first album by Orbison on the Sun Records label in 1961, at a time when Orbison had already moved to the Monument label. Sun Records owner Sam Phillips had a collection of songs Orbison had recorded at Sun between 1956 and '58. Phillips capitalized on the national recognition Orbison had achieved at Monument through three major hit singles in 1960 and '61 that had gone to the top of the Billboard charts.
Document 4: Loretta Lynn: Lynn's relationship with the Wilburn Brothers and her appearances on the Grand Ole Opry, beginning in 1960, helped Lynn become the number one female recording artist in country music. Her contract with the Wilburn Brothers gave them the publishing rights to her material. She was still fighting to regain these rights 30 years after ending her business relationship with them but was ultimately denied the publishing rights. Lynn stopped writing music in the 1970s because of these contracts. Although Kitty Wells had become the first major female country vocalist during the 1950s, by the time Lynn recorded her first record, only three other women -- Patsy Cline, Skeeter Davis, and Jean Shepard -- had become top stars. Lynn joined The Grand Ole Opry on September 25, 1962.
Document 5: Hello Walls: "Hello Walls" is an American country music song first recorded by Faron Young. It became a massive hit in 1961, reaching #1 country and spent 23 weeks on the chart. On other charts, it peaked at #12 pop, and was Young's only top 40 pop hit in the United States. “Hello Walls” introduced its songwriter – Willie Nelson – to a national audience.
Document 6: Tornadoes in the United States: Most tornadoes in the United States occur east of the Rocky Mountains. The Great Plains, the Midwest, the Mississippi Valley and the southern United States are all areas that are vulnerable to tornadoes. They are relatively rare west of the Rockies and are also less frequent in the northeastern states. Tornado Alley is a colloquial term for an area particularly prone to tornadoes. There is no officially defined 'Tornado Alley' -- at its broadest this area stretches from North Texas to Canada with its core centered on Oklahoma, Kansas and northern Texas. Another highly significant region -- colloquially known as Dixie Alley -- is the southern United States and particularly the northern and central parts of Alabama and Mississippi. Florida is one of the most tornado prone states. However, Florida tornadoes only rarely approach the strength of those that occur elsewhere.
Document 7: Hank Snow discography: Hank Snow was a Canadian country music artist. His discography consists of 46 studio albums and 89 singles. Of his 89 singles, seven reached number 1 on the U.S. "Billboard" Hot Country Songs charts and two reached number 1 on the Canadian "RPM" Country Tracks chart. Snow spent his entire recording career with RCA Victor records.
Document 8: 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 9: The Name of the Game Was Love: "The Name of the Game Was Love" is a single by Canadian country music artist Hank Snow. The song peaked at number 1 on the "RPM" Country Tracks chart. It also reached number 16 on the "Billboard" Hot Country Singles chart in the United States.
Document 10: 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.
Document 11: On the Road Again (Willie Nelson song): The song, about life on tour, came about when the executive producer of the film Honeysuckle Rose approached Nelson about writing the song for the film's soundtrack. ``On the Road Again ''became Nelson's 9th Country & Western No. 1 hit overall (6th as a solo recording act) in November 1980, and became one of Nelson's most recognizable tunes. In addition, the song reached No. 20 on the Billboard Hot 100, and No. 7 on the Adult Contemporary chart. It was his biggest pop hit to that time and won him a Grammy Award for Best Country Song a year later.
Document 12: The Story of My Life (Marty Robbins song): The song became a 1957 hit for US country singer Marty Robbins, which peaked at number one on the US country chart for four weeks and reaching number fifteen on the Billboard Top 100 and number two on Australian Singles Chart.
Document 13: 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 14: Tennessee: Most of the state has a humid subtropical climate, with the exception of some of the higher elevations in the Appalachians, which are classified as having a mountain temperate climate or a humid continental climate due to cooler temperatures. The Gulf of Mexico is the dominant factor in the climate of Tennessee, with winds from the south being responsible for most of the state's annual precipitation. Generally, the state has hot summers and mild to cool winters with generous precipitation throughout the year, with highest average monthly precipitation generally in the winter and spring months, between December and April. The driest months, on average, are August to October. On average the state receives 50 inches (130 cm) of precipitation annually. Snowfall ranges from 5 inches (13 cm) in West Tennessee to over 16 inches (41 cm) in the higher mountains in East Tennessee.
Document 15: Hello Love (song): "Hello Love" is a 1974 single by Hank Snow. "Hello Love" was Snow's seventh and final number one on the U.S. country singles chart, and his first number one in twelve years. The single stayed at number one for a single week and spent a total of ten weeks on the chart.
ground_truth: 15
sub_queries: Hello Love >> performer Answer: Hank Snow
What city did Hank Snow live when he died? Answer: Tennessee
How many tornadoes strike in Tennessee in an average year? Answer: 15