Electric-car maker Tesla Motors said it delivered 14,370 vehicles from April through June, made up of 9,745 Model S sedans and 4,625 Model X utility vehicles.

That number means the company missed its second-quarter production target of 17,000 cars.

During the first six months of this year, Tesla has delivered 29,190 cars.

That's notably less than half the projected full-year number of 80,000 to 90,000 it announced at its 2015 earnings call in February.

Issued on Sunday, the company's deliveries announcement led off with production rates, which Tesla says are now "just under 2,000 vehicles a week."

Delivery rates weren't mentioned until the third of its three paragraphs.

Tesla noted that while it had delivered fewer than 15,000 cars, it had produced 18,345, with more than 5,000 vehicles still in transit to customers.

"Due to the steep production ramp," the company said, "almost half of the quarter's production occurred in the final four weeks."

Keeping its assembly lines operating at a steady pace has been a continuing challenge for Tesla, especially with the launch of the complex Model X crossover utility vehicle.

It has now missed initially announced targets not only for quarterly production but for last year's total as well.

"This is not the first time Tesla has missed an aggressive target," wrote financial analysts at Deutsche Bank in a report issued over the weekend.

"Suppliers continue to suggest Tesla has had difficulty maintaining steady production of Model X," the report noted, "with some estimating 'up time' is as low as 50 percent."

Since the first one was presented to its buyer last September, the company has delivered more than 7,200 Model X vehicles—despite 20,000 deposits for the vehicle, according to its own statement in February 2015.

Tesla stopped commenting on the numbers of reservations it had in hand for the Model S and Model X more than a year ago.

CEO Elon Musk has acknowledged that the design of the Model X was overly complex and has proved extremely challenging to produce.

Its rear "falcon doors" in particular, which open from the roof and are hinged in the middle, have been a source of fit and reliability complaints on Tesla owner forums.

The company remains confident that it will build and deliver roughly 50,000 vehicles during the second half of this year.

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That would bring its annual total to almost 80,000, or right on the low end of its full-year projection.

Tesla has said it plans to deliver as many as 400,000 vehicles by 2018, two years ahead of its earlier target of 2020, the bulk of them its planned $35,000 Model 3 sedan.