Duplicate pages

Why are there several duplicate pages listed in the stats. I can see that one is www. and one is not, but they are the same page and it is misleading especially as they are not listed together. Is there a way of combining them?
You may feel it's the same page but since it's different urls they are considered different pages - in fact duplicate content pages.

You need to handle this on your site as such. Pick the canonical form you like (with www or without www) and 301 redirect the other one to it. Ensure all navigation is consistently using the preferred canonical form.

The advice is not just for Statcounter, it's for proper indexing and ranking in search engines.

When you have 2 distinct urls or more displaying the same page of content this means each of those distinct urls are canonical urls of each other.

Typically www.example.com and example.com will produce 2 sets of canonical urls. This results in duplicate content being found on a site.
In addition to that, having both http and https protocols on the site doubles again the number of urls showing the same content.

The solution is to canonicalize each url: to pick a preferred form (and protocol) and enforce it.

You enforce it by using one or several or all of these methods. From most effective to least effective:
301 redirection between the non-preferred form to the preferred form for each url (e.g. non-www to www or www to non-www). How it's done depends on the type of server. To fix canonical issues on an Apache server: https://sites.google.com/site/onlyv...sues-www-vs-non-www-and-more-on-apache-server . For other types of servers you need to ask your hoster how to achieve the same thing.

Using a canonical link tag in the source code of each page providing the preferred url for that particular page. This helps also in cases where duplication happens also as a result of various query strings that may be appended to the url without there being any difference in the page content that's displayed. This helps in Google but maybe not in other search engines.
Setting a preferred domain in Webmaster Tools - this means picking which of www or non-www you prefer to see indexed. This helps in Google but not at all in any other search engines.

Maintaining a rigorous consistent navigation on the site, where all navigation links are fully qualified urls (i.e rather than relative to the root or the current folder) and using the preferred version of the domain at all times. This is good practice anyway. It may help with indexing just one version of the domain (www or non-www) but it's no guarantee. Suffice somebody post a link to the "wrong" version somewhere and this opens the gates to crawling that as well unless navigation links are consistently using one form only.