Weaker economic data, especially from the disappointing jobs numbers, and another Eurozone scare dragged on equity exchange traded funds in April. Meanwhile, fixed-income funds helped picked up the slack as investors maintained a “risk-off” safety net.

At the end of April, total assets in U.S.-listed ETF and exchange traded note products totaled about $1.204 billion, an increase of 6% year-over-year, according to the ETF Industry Association. [ETF Performance Report: April Showers]

ETPs brought in $3 billion in April, bringing year-to-date inflows to $58.9 billion, which is already higher than $50.7 billion in inflows for all of 2011.

Listed trading volumes continue to decline, but average daily volumes for ETFs have risen 0.5% year-to-date, compared to the same period last year, writes Nicholas Colas, Chief Market Strategist at ConvergEx, in a research note.

“Exchange Traded Funds have been one of the few real bright spots in the world of asset management over the past few tumultuous years for the business,” Colas writes. ” The domestic ETF industry is essentially the Energizer Bunny of the U.S. capital market – asset growth keeps going and going.”

Fixed-income ETPs continued to draw in heavy flows, adding almost $5 billion in new assets, which marks the 16th consecutive month of new inflows. However, outflows in risky assets, such as the the $1.2 billion from U.S. equity ETPs and $1 billion drain in  commodities, offset some of the overall gains.

It is interesting to note that the largest ETF provider, BlackRock, has added $917 million in new assets, while Vanguard, the third largest provider, experienced the highest inflows for the month. In contrast, State Street Global Advisors, the second largest provider, saw $1.3 billion in outflows.

As of April 30, there were 1,458 U.S.-listed ETPs, compared to 1,216 products over the same time last year, or a 20% rise in fund products. So far this year, 105 new products have been launched, and only 16 were de-listed.

As the ETF universe keeps expanding, more hands will be needed to guide the fledgling industry. If you are interested in taking part of the ETF growth story, take a look at our ETF jobs listings page.

For more information on ETF fund flows, visit our ETF performance reports category.

Max Chen contributed to this article.