TABLE 6. The Five Shortest Paths by Decade†.
| Subtype | Decade | Path length |
|---|---|---|
| 1930–1939 | ||
| H1N1 | A/swine/USA/1976-MA/1931 | 2066 |
| H1N1 | A/swine/USA/1976/1931 | 2072 |
| H1N1 | A/swine/1931 | 2100 |
| H1N1 | A/swine/Ohio/23/1935 | 2108 |
| H1N1 | A/Phila/1935 | 2308 |
| 1940–1949 | ||
| H1N1 | A/swine/Jamesburg/1942 | 2073 |
| H1N1 | A/AA/Marton/1943 | 2367 |
| H1N1 | A/Bellamy/1942 | 2401 |
| H1N1 | A/Weiss/1943 | 2405 |
| H1N1 | A/Hickox/1940 | 2415 |
| 1950–1959 | ||
| H1N1 | A/swine/Wisconsin/1/1957 | 2056 |
| H1N1 | A/Albany/13/1951 | 2704 |
| H1N1 | A/FortWorth/1950 | 2764 |
| H1N1 | A/Malaya/302/1954 | 2824 |
| H1N1 | A/Malaysia/1954 | 2824 |
| 1960–1969 | ||
| H1N1 | A/swine/Wisconsin/1/1961 | 2023 |
| H3N2 | A/HongKong/1–8-MA21–1/1968 | 2894 |
| H3N2 | A/HongKong/1–8-MA21–3/1968 | 2911 |
| H3N2 | A/Albany/10/1968 | 2912 |
| H3N2 | A/Beijing/1/1968 | 2912 |
| 1970–1979 | ||
| H1N1 | A/swine/Minnesota/5892–7/1979 | 2005 |
| H1N1 | A/swine/Tennessee/10/1976 | 2015 |
| H1N1 | A/swine/Nebraska/123/1977 | 2021 |
| H1N1 | A/swine/Minnesota/27/1976 | 2021 |
| H1N1 | A/swine/Tennessee/17/1976 | 2023 |
| 1980–1989 | ||
| H1N1 | A/swine/Iowa/17672/1988 | 1921 |
| H1N1 | A/turkey/NC/17026/1988 | 1934 |
| H1N1 | A/swine/Wisconsin/1915/1988 | 1953 |
| H1N1 | A/Swine/Indiana/1726/1988 | 1958 |
| H1N1 | A/swine/Kansas/3024/1987 | 1972 |
| 1990–1999 | ||
| H3N2 | A/Swine/Iowa/533/99 | 1417 |
| H3N2 | A/Swine/Minnesota/593/99 | 1425 |
| H3N2 | A/Swine/Nebraska/209/98 | 1441 |
| H1N1 | A/turkey/IA/21089-3/1992 | 1910 |
| H1N1 | A/swine/Maryland/23239/1991 | 1911 |
| 2000–2009 (excludes bottlenecks) | ||
| H1N2 | A/duck/NC/91347/01 | 954 |
| H1N1 | A/swine/OH/511445/2007 | 1053 |
| H3N1 | A/swine/MI/PU243/04 | 1327 |
| H3N1 | A/swine/IN/PU542/04 | 1384 |
| H1N1 | A/swine/Ontario/53518/03 | 1478 |
†
Only the first of any set of paths originating from same location.