I ran the same analysis on FICO trends in LC's historical loan database. Here are the results, broken down by year of issue.
Down Flat Up Total Down Flat Up
2007 374 59 170 603 62.0% 9.8% 28.2%
2008 1552 101 740 2393 64.9% 4.2% 30.9%
2009 3208 204 1869 5281 60.7% 3.9% 35.4%
2010 7353 466 4718 12537 58.7% 3.7% 37.6%
2011 12797 811 8113 21721 58.9% 3.7% 37.4%
2012 28824 2316 22227 53367 54.0% 4.3% 41.6%
2013 59770 7533 67453 134756 44.4% 5.6% 50.1%
2014 56393 12027 92811 161231 35.0% 7.5% 57.6%
My take: Depends on when the loan issued.The years that we know had poor loan performance, ie 2007,8,9,10 had more loans with credit scores going down during the loan. This trend has gradually reversed as the economy has improved.
Caveats: Many of these loans are uncompleted. I compared the last FICO to the issue FICO. I used the 9/2014 database. I included all loans, no matter what their status. Loans in later years are mostly not yet completed, so we're comparing changes over different length periods of time (ie for the 2014 loans, the change will only be over a few months, whereas for 2007 loans its almost always over 3 years). Still, it gives you a direction.
Conclusion re my portfolio: Although I've been an LC investor for many years, I greatly increased my investment during 2014, so my portfolio is heavily weighted with 2014 loans. Looks like my portfolio credit trends are in line with the whole-LC 2014 portfolio. Not a very exciting result, but at least I'm not doing worse than everybody else.

PS: Sorry for the left justified numbers. I just copy/pasted from Excel, and that produces tab-delimited columns, which works reasonably well in a CODE block on the forum.