Subject: Does the amount of salt in a water solution affect evaporation rates?

That is the question that I am pondering.  I conducted the experiment 
3 times, and I found out that the solution with 0% salt had a faster 
evaporation rate than those of 5%, 10% and 15% (all were with 500 mL 
of water).  I have been searching and thinking of reasons why this is 
so, but I have been unlucky in finding the answer.  Is there a reason 
why the evaporation rate was different?  Or is the evaporation rate 
the same?  I tried to control all of the variables.  I kept them in 
the same window with the same amount of light, I used identical 
glasses, and I used the same water.  The only variable was that of the 
salt solution.  Please help me because I do not know of anyone who 
ever did this experiment, and I cannot think of the reasonable 
reason(s).

Re: Does the amount of salt in a water solution affect evaporation rates?