Member rank is automatically calculated depending on the total point earned by a member. You may see that 2 or more person will be having same rank, this is because the rank is updated once in a week exactly saying rank is updated every sunday.
Rank position depends only on the points earned by a member.
As mentioned by the webmaster, the rankings are calculated according to the points earned by each member. This ranking usually changes every sunday preferably within evening. This is a better method to judge the level of the member and where one stands in KSP. This is very helpful in knowing ones capacity. As you are already in the Rank of 7, I am sure with you hard work and more resource postings, you can get the highest rank.
Best wishes for it.