lgd is outside the for loop with no buffer array to hold the data. This is why only the last value is being displayed. While this would work if the position of lgd was changed to inside the for loop any inclusion of a for loop with the plot command makes me a little nervous due to the computational resorces required.
I would suggest trying something like this instead: (note the changes to 'legend')
EC = [0.0052 0.0078 0.0104 0.0130 0.0156 0.0182 0.0208 0.0234 0.0260 0.0286];
There may need to be some additional formatting however that should display everything. Let the forumm know how it goes and if you need any other help with it.