Displaying change via 'slope'?

[hexa]

I started running a few weeks back and I want to know if I'm improving speed-, distance- and duration-wise.

I have a set of data like these (this is bogus data), currently in Excel:

1. 15
2. 13
3. 16
4. 17
5. 15
6. 15
7. 14
8. 17
9. 17

and I want to know if these numbers get larger with time. How would I do that. I calculated the slope with ongoing number on the x-axis and the changing value on the y-axis. If this is a correct way, what does that number actually tell me regarding the grade of improvement? Is there a much better way to do so?

 

[B-Con]

Without knowing what generated these numbers it's impossible to know for sure whether or not they are getting larger, but you can still make a decent guess using slopes.

The way I would do it would be to calculate the slope between each point and take the average, you should get a good idea as to how the number set is behaving. Given how close your actual values are, though, and how few of them you have, it may not be terribly accureate, however.