Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Tenure | Coach | Years | Record | Pct. |
| --- | --- | --- | --- | --- |
| 1892 | Shelby Fletcher | 1 | 1–0 | 1.000 |
| 1893 | W. M. Walker | 1 | 4–6–1 | .409 |
| 1894 | J. H. Lyons | 1 | 10–3 | .769 |
| 1895 | J. F. Jenkins | 1 | 9–3 | .750 |
| 1896 | Eli Abbott | 1 | 5–5 | .500 |
| 1897 | "Kid" Peeples | 1 | 10–0 | 1.000 |
| 1898 | Joseph Black | 1 | 2–3 | .400 |
| 1899 | F. C. Owen | 1 | 3–6 | .333 |
| 1900 | Ardis Smith | 1 | 9–3 | .750 |
| 1901–1905 | Thomas Stouch | 5 | 49–25–1 | .660 |
| 1906 | Schwartz | 1 | 4–16–1 | .214 |
| 1907–1910 | J. W. H. Pollard | 4 | 66–22–1 | .747 |
| 1911 | Guy Lowman | 1 | 12–5 | .706 |
| 1912–1915 | D. V. Graves | 4 | 66–30–1 | .686 |
| 1916–1919 | B. L. Noojin | 4 | 55–18 | .753 |
| 1920 | Gordon W. Lewis | 1 | 15–2 | .882 |
| 1921–1923 | Charles Bernier | 3 | 28–35–4 | .448 |
| 1924–1927 | Wallace Wade | 4 | 61–32–2 | .653 |
| 1928 | Hank Crisp | 1 | 12–7–2 | .619 |
| 1929–1930 | Jess Neely | 2 | 28–15–2 | .644 |
| 1931–1932 | Sam Hinton | 2 | 23–7–2 | .750 |
| 1933–1934 | Jennings B. Whitworth | 2 | 21–11 | .656 |
| 1943 | Paul Burnham | 1 | 12–6 | .667 |
| 1946 | Dixie Howell | 1 | 13–7 | .650 |
| 1935–1942\n1947–1963 | Tilden Campbell | 25 | 355–168–4 | .677 |
| 1964–1969 | Joe Sewell | 6 | 106–79 | .573 |
| 1970–1979 | Hayden Riley | 10 | 236–206–1 | .533 |
| 1980–1994 | Barry Shollenberger | 15 | 487–334–1 | .593 |
| 1995–2009 | Jim Wells | 15 | 625–322 | .656 |
| 2010–present | Mitch Gaspard | 4 | 133–115 | .536 |
| Totals | 30 coaches | 121 seasons | 2,461–1,490–23 | .623 |
Question:
what was the average number of years served by a coach?
Answer:
4