In October, Google made Google Webmaster Tools available to all users in Google Analytics, allowing everyone to surface Google search data in new Search Engine Optimization reports. Webmaster Tools will update how they calculate data to make it better match expectations about what a search engine ranking really means.
Based on their research, the answer to the question ‟What is your rank in search results?” is the first position of a link to your site. Previously Google reported the average position of all links to your site. Now your Google Analytics reports will be updated to reflect the first position.
This new method of calculation will more accurately match your expectations about how a link’s position in Google Search results should be reported.
How will this affect my Google Analytics data?
This change will affect your Search Engine Optimization reports, when your data in Google Analytics Search Engine Optimization reports will be calculated using the new method. Historical data will not change.
For more information visit Google Analytics Official Blog