I have datasets for a bunch of years and am comparing different metrics for the various years. I want to determine whether the change from one year to the next is statistically significant.
For example, in Year 1 there are 100 calls and in Year 2 there are 105 calls. I want to find out if the increase of 5 in the first two years is statistically significant.
Similarly, the average time in Year 1 is 2 minutes and the average time in Year 2 is 2.2 minutes. Is this .2 increase statistically significant.
I also calculate 90th percentiles. If 90% of the calls for Year 1 are below 3 minutes and 90% of the calls in Year 2 are below 3.1 minutes, I want to know if the .1 minute increase is significant.

I hope someone out there can help me!

Thanks so much.