Wall Street is raising its price forecasts for next year after crude on the New York Mercantile Exchange reached $90.76 a barrel on Dec. 7, the highest level since Oct. 8, 2008.

The price California farmers get for their milk is tied to sales of butter and cheddar cheese on the Chicago Mercantile Exchange combined with prices for dry whey and dry milk.

Since 2004 the near tripling of trading in oil on the New York Mercantile Exchange (NYMEX), the world's biggest market for the stuff, has neatly coincided, with a tripling in the price.