NFL - Highest Win % over a 20-year intervals since the merger

Which teams have had the best win% over a 20-year period since the merger in 1970?

49ers - 13x

Pats - 9x

Dolphins - 6x

Steelers - 4x

Broncos - 1x

Note: Patriots have had the overall best win% in the Top 6, 20-years intervals

BY WIN%
RANK	TEAM	FROM	TO	G	W	L	T	PCT
1	NWE	2001	2020	320	239	81	0	0.747
2	NWE	2000	2019	320	237	83	0	0.741
3	NWE	1999	2018	320	233	87	0	0.728
4	NWE	1998	2017	320	231	89	0	0.722
5	NWE	1997	2016	320	228	92	0	0.713
6	NWE	1996	2015	320	225	95	0	0.703
7	SFO	1983	2002	319	223	95	1	0.701
8	SFO	1981	2000	312	217	94	1	0.697
8	SFO	1980	1999	312	217	94	1	0.697
10	SFO	1982	2001	312	216	95	1	0.694
11	SFO	1984	2003	319	220	98	1	0.691
11	SFO	1979	1998	312	215	96	1	0.691
13	NWE	1995	2014	320	219	101	0	0.684
14	NWE	1994	2013	320	217	103	0	0.678
15	MIA	1971	1990	298	200	96	2	0.674
16	MIA	1970	1989	296	198	96	2	0.672
17	MIA	1972	1991	300	198	101	1	0.662
18	SFO	1978	1997	312	205	106	1	0.659
19	NWE	1993	2012	320	210	110	0	0.656
20	SFO	1985	2004	319	207	111	1	0.650
21	MIA	1973	1992	302	195	106	1	0.647
22	PIT	1992	2011	320	204	115	1	0.639
23	SFO	1977	1996	310	197	112	1	0.637
24	MIA	1974	1993	304	192	111	1	0.633
25	SFO	1986	2005	319	201	117	1	0.632
26	SFO	1976	1995	308	193	114	1	0.628
27	MIA	1975	1994	306	191	114	1	0.626
28	PIT	1991	2010	320	199	120	1	0.623
29	SFO	1987	2006	319	198	121	0	0.621
30	PIT	1990	2009	320	196	123	1	0.614
30	PIT	1989	2008	320	196	123	1	0.614
33	SFO	1988	2007	320	190	130	0	0.594
33	DEN	1988	2007	320	190	130	0	0.594
BY YEAR
RANK	TEAM	FROM	TO	G	W	L	T	PCT
1	NWE	2001	2020	320	239	81	0	0.747
2	NWE	2000	2019	320	237	83	0	0.741
3	NWE	1999	2018	320	233	87	0	0.728
4	NWE	1998	2017	320	231	89	0	0.722
5	NWE	1997	2016	320	228	92	0	0.713
6	NWE	1996	2015	320	225	95	0	0.703
13	NWE	1995	2014	320	219	101	0	0.684
14	NWE	1994	2013	320	217	103	0	0.678
19	NWE	1993	2012	320	210	110	0	0.656
22	PIT	1992	2011	320	204	115	1	0.639
28	PIT	1991	2010	320	199	120	1	0.623
30	PIT	1990	2009	320	196	123	1	0.614
30	PIT	1989	2008	320	196	123	1	0.614
33	SFO	1988	2007	320	190	130	0	0.594
33	DEN	1988	2007	320	190	130	0	0.594
29	SFO	1987	2006	319	198	121	0	0.621
25	SFO	1986	2005	319	201	117	1	0.632
20	SFO	1985	2004	319	207	111	1	0.650
11	SFO	1984	2003	319	220	98	1	0.691
7	SFO	1983	2002	319	223	95	1	0.701
10	SFO	1982	2001	312	216	95	1	0.694
8	SFO	1981	2000	312	217	94	1	0.697
8	SFO	1980	1999	312	217	94	1	0.697
11	SFO	1979	1998	312	215	96	1	0.691
18	SFO	1978	1997	312	205	106	1	0.659
23	SFO	1977	1996	310	197	112	1	0.637
26	SFO	1976	1995	308	193	114	1	0.628
27	MIA	1975	1994	306	191	114	1	0.626
24	MIA	1974	1993	304	192	111	1	0.633
21	MIA	1973	1992	302	195	106	1	0.647
17	MIA	1972	1991	300	198	101	1	0.662
15	MIA	1971	1990	298	200	96	2	0.674
16	MIA	1970	1989	296	198	96	2	0.672