Looking back on own photos - do I improve?

Recently I have scanned through the old photos I have made over past years to sort the tags out a little bit.
Then I came to the idea: if I take the photos belonging to a certain category and put it on a timeline, will I see any trend? Will I see improvement of my photographic skills, for example? Is there anything that I could name as a 'constant element', a style?
So I took the photos tagged as the 'landscape' and taken in years 2007-2012. And it was an interesting excercise. Some observations:

• Composition of my landscape photos improves over the years. 
• I need to work on making the landscapes more interesting. I have a tendency to leave too much empty space in the photo, making the picture not as interesting as it could be. How to improve? Studying work of the best in business, scout for the better landscapes is the plan for the coming period.
• The lighting on most of my pictures is, well, not so good. Here the remedy is simple, I think - get up early, be on a location at the sunrise. Also something easy to try.

To summarize: it is worth repeating this excercise more frequently, it definitely helps.