Earlier this  year, Uber secured venture capital investments worth $2 billion, which value the seven-year-old ride-sharing company at an astronomical $62 billion. General Motors, which makes some of the autos that Uber's customers will actually ride in, is worth only $50 billion by comparison. Still, Uber's number may portend some trouble for the bulk of startups looking for investment capital.

Namely, venture capital is getting scarcer for younger companies, and valuations are deflating, even as many late-stage funding rounds to private companies ratchet ever higher.

That's the news from the latest report from PitchBook, a venture capital research firm, which released data on valuation trends on Wednesday. The report compares full-year 2015 data to the first two full months of 2016 to make guesses about the direction of investing for the rest of the year.

Through February, 2016, the median pre-money valuation for a Series D or later round was $229 million, an increase of 27 percent compared with $180 million for the full-year 2015. By contrast, the median seed round valuation of $7 million increased 17 percent over the same time period.

Valuations dropped for old and young companies alike. The median step-up, or valuation prior to funding, for late stage investments was worth 1.3 times the previous valuation through February compared with 1.4 times in 2015. The median early stage step-up was worth 1.6 times the previous figure, compared with 1.8 in 2015.

In tandem with the decreasing valuations, the number of down rounds, or investments that are under previous cash infusions, has also increased to 16.3 percent of total funding in the first two months of 2016, according to the report. That compares with down rounds worth 15 percent of total funding for the full year 2015.

Meanwhile, the average age of firms that received late stage venture capital increased to 10 years in the early part of 2016, up from 8.8 years in 2015. The average age for seed funding decreased by 2 months to 2.3 years for seed funding, but it increased by five months to 4.7 years for the average Series A round, over the same time period.

Generally speaking, venture capital investors are looking for robust firms with proven business models, the report surmises. Who could blame them? "The only startups to receive funding in today's uncertain climate are the ones best primed in VCs' judgment to survive any potential economic downturn," writes Garrett James Black, a senior analyst for PitchBook, who compiled the report.

The median late stage round was $31 million, compared with $5.5 million for the median seed round, and $14.4 million for the median Series A in 2015, according to PitchBook.