Total Number of NES Games By Year

Including 675 licensed games:

Year	Games	PCT
1985	18	2.7%
1986	18	2.7%
1987	55	8.1%
1988	63	9.3%
1989	96	14.2%
1990	168	24.9%
1991	105	15.6%
1992	97	14.4%
1993	43	6.4%
1994	12	1.8%
Total	675	100.0%

The three biggest years for NES releases were 1990, 1991, and 1989 in that order. It's no surprise that the year before the SNES launched was the biggest year.

29.3% of games were released in September 1991 or later, after the SNES came out (in August).