Nico Rosberg says he rates his 2015 campaign "seven-and-a-half" out of ten after falling short of the world championship for a second year in a row.

Rosberg was beaten to the championship by Mercedes team-mate Lewis Hamilton but won the final three races of the season once the British driver had wrapped up the title in Austin. He finished the year with a tally of six race victories to Hamilton's ten and was out-qualified 12-7, though he finished with a run of six consecutive pole positions.

Asked how he rated his season, Rosberg replied: "I don't know, seven-and-a-half or something like that ... seven ... The problem is that the other guy had a higher number, but it was okay."

Rosberg fell short of his 2014 standards, which saw him out-qualify Hamilton and take the title fight to the final race in Abu Dhabi. He feels like that experience paid dividends throughout 2015.

"It's difficult to compare, but I'm sure I've improved as a driver with last years' experience."

Much has been made of Rosberg's end of season form and whether it will swing momentum in his favour when the 2016 season begins in Melbourne. The German says it just came down to him being faster than Hamilton in the closing races but he admits the changes that come with a new car will lead to a "partial" reset ahead of the 2016 Australian Grand Prix.

"The rules are staying the same for next year and whatever is happening this year applies for next year as well, so for sure that's not my priority ... [Winning] does come into it, but that's not the main factor. Over the winter, with the new car so much will changes. It's not a complete reset, but it's partial."