It's no secret that actively managed mutual funds have been seeing outflows as investors increasingly favor passive index funds. Now, a study by Morningstar has shown that investors are not only dumping high-priced funds in U.S. stock categories, but also for foreign stocks and bonds, too. At the same time, investors in 2016 ended up paying the lowest fund expenses on record, overall. The reason for this is not that funds are turning around and lowering their fees, as a general rule, but rather that investors are choosing to ditch high-fee funds for ones with lower associated costs. These are some of the funds with the highest aggregate levels of redemptions for the year ending April 30, 2017.

PIMCO Total Return

PIMCO's Total Return fund topped the list by Morningstar. This fund focuses on intermediate-term bonds and featured total net assets of $73.67 billion as of the time of the report. Over the course of the year up to April 30, 2017, this fund saw net outflows of more than $15 billion, constituting a change of 17.2% of net assets.

Templeton Global Bond

Templeton's internationally-focused Global Bond fund was next up on the list in terms of total outflows. Though it saw less money in total leave the fund as compared with PIMCO ($13.99 billion over the year in question), that net outflow was a larger percentage. Templeton's Global Bond fund has total net assets of just under $40 billion, so the loss was around 26% overall.

BlackRock Global Allocation (BLK)

A world allocation fund of approximately the same size as Templeton's fund listed above, BlackRock GLobal Allocation also lost significant investor interest for the year in question. This fund dropped by 21.5%, seeing investors pull close to $11 billion in assets during that time period.

Fidelity Contrafund

As one of the largest funds on Morningstar's list, Fidelity's Contrafund is placed in the report's "large growth" category. Its $110.69 billion in AUM did not stop the fund from losing $10.43 billion from investors, a drop of 8.6%.

Vanguard Institutional Index

The large blend fund at Vanguard is the largest on Morningstar's survey, with total assets under management of more than $225 billion. For this reason, the percentage by which it declined thanks to investor withdrawals leading up to the end of April of this year is the smallest at just 4.2%. Still, the fund saw the fifth-highest absolute withdrawal amount during this time, with investors pulling $9.9 billion from the fund.

Of the top 10 funds on Morningstar's list, eight are actively managed, and seven of the most-purchased funds during this time were index funds.