logs older than 7 days

I have a Fortigate 101F running v6.4.6.  A 360GB drive that's 1% used.  I've changed maximum-log-age to 365.  However, under Log & Report -> Events, only 7 days of logs are shown.  Below is my "log disk setting".

config log disk setting
set status enable
set ips-archive enable
set max-policy-packet-capture-size 100
set log-quota 0
set dlp-archive-quota 0
set report-quota 0
set maximum-log-age 365
set upload disable
set full-first-warning-threshold 75
set full-second-warning-threshold 90
set full-final-warning-threshold 95
set max-log-file-size 20
set roll-schedule daily
set roll-time 00:00
set diskfull overwrite
end

What could be the problem??