This analysis is quite late, a month late in fact.
Here are our June harvest numbers, by year:
2007 -- 1259
2008 -- 1538
2009 -- 299
2010 -- 536
2011 -- 273
Strangely, our best June number was in 2008. That was our worst harvest year, by the numbers. We harvested just over 4500 tomatoes that year.
Based on my memory at the end of June, I wasn't worried about the poor numbers. The tomato plants were very tall and looked quite healthy. This is just a reflection of a late planting (early to mid April) than anything else.