More comments from Federal Reserve Bank of San Francisco President John Williams:
- September would be a 'very plausible' time to start raising interest rates
- Still see two rate hikes in 2015, but depends on economic data
- Sees reaching inflation goal in year and a half, full employment well before that
- Sees 50 pct possibility inflation will rise above 2 pct by end of 2016
- Situation in Greece is "a little less worrisome" than last week
