I have a dataset of the following form:
Month 2000 2001 ----- ------ ------ March 100.71 101.54 April 102.56 103.01 May 101.45 101.23 June 102.78 103.37 July 104.79 105.62 August 105.61 105.63
Which is the average amount of a chemical taken at different months over 2000 and 2001.
I want to formally test whether the average amount of the chemical during 2001 is no greater than that of 2000. I was considering using the Wilcoxon Signed-Rank test but was unsure whether this test is the most suitable. I was also unsure whether this data is paired.
Because the sample size is small, I was under the impression that a t-test is out of the question and that a non-parametric test is required. So is the Wilcoxon Signed-Rank Test the best test to use in this case?