Half of this year is now gone, which means it’s time once again to look at sales of plug-in electric cars–both for June and for the first six months of 2012.

Coming off a streak of low sales months, 535 Nissan Leafs were sold in June, less than one-third the 1,708 Leafs delivered in June 2011.

This means that 3,148 Leafs have been sold in the first half of 2012, fewer than for the same six-month period in 2011, by which time 3,875 Leafs had been delivered.

The continuing low numbers for 2012 make it seem challenging indeed for Nissan to meet its stated goal of selling 20,000 Leafs in the U.S. this year.

Last month, however, a Nissan executive modified the claim to say that would be 20,000 Leafs by the end of the 2012 fiscal year–which extends through March 2013.

Continuing recently stronger sales compared to last year, 1,760 Chevrolet Volt range-extended electric cars were delivered last month.

via June Plug-In Electric Car Sales: Volt Stays Strong, Leaf Low.