SQL and a Running/Moving Total

[Mark Allen <scprideandms@xxxxxxxxx>]

Table has 3 columns,Name,year,count  and I need a total of the "count" field
for each name over a 3 yr period, if there are NOT 3 years available then no
output row.

Example:
Bill  1990    72
Bill  1991    73
Bill  1992    71
Bill  1993    55
Bill  1994    78
Bill  1995    73
Stan  1990    130
Stan  1991    122
Stan  1992    100
Stan  1993    115
Stan  1994    101
Stan  1995    112

What I want from the SQL output  is

Bill  1990    216
Bill  1991    199
Bill  1992    204
Bill  1993    206
Stan  1990    352
Stan  1991    337
Stan  1992    316
Stan  1993    328