Third-party distribution channel sales from broker-dealers, registered investment advisors and banks help drive exchange traded fund usage to all-time highs in 2016.

In 2016, over $610 billion, or 85% of the $724 billion of net new asset flows through third-party channels, went into index funds or passive ETFs, according to Broadridge Financial Solutions.

Independent broker-dealers, wirehouse firms, RIAS and discount brokerage firms experienced almost 82% of net new asset flows into passive funds and ETFs while institutional banks, private banks and trust departments had 90% of net new flows into passive products.

Driving the increased inflows into passive index-based products, expense ratios or management fees have been steadily driven lower, especially as ETF providers engage in a so-called fee war that has helped push annual expenses every closer to 0% while some have even partnered with brokerage platforms to offer commission-free trades to help drive investment interest.