"Angels are learning more about how much and when to invest.," she said.
Angels' portfolios of new investments grew steadily between 2008 and 2010, in particular.
"A significant number of the most active angel investors are shifting their main focus to supporting their existing companies," she said in a statement.
This was a rational response to the recognition by angels that companies required follow-on funding, and a lack of material follow-on money from other sources in New Zealand.
"The trends we are seeing in angel investing highlights the need for later stage funds - venture capital funds - to provide the larger investment capital to develop the companies which angel investors have been backing," Banga said.
Angel investors have cumulatively invested $220m into high-growth companies since 2006, in an average deal size of $540,000. The average deal size in 2011 was $323,549.
Of the $30.7m invested last year, $11.7m was into first round investments and $19.0m comprised follow-on investments in existing companies.
In terms of the stage of investment, $6.6m was seed investment, $23.8m was at the start-up stage, $360,000 at the early expansion level, and nil at the expansion stage, NZVIF said.