That is such a vague statement, I highly recommend disregarding it entirely, as it is impossible to know what they meant. Their goal is to convince you that index funds are the way to go, but depending on what they consider an 'active trader', they may be supporting their claim with irrelevant data
Their definition of 'active trader' could mean any one or more of the following: 1) retail investor 2) day trader 3) mutual fund 4) professional investor 5) fund continuously changing its position 6) hedge fund. I will go through all of these.
1) Most retail traders lose money. There are many reasons for this. Some rely on technical strategies that are largely unproven. Some buy rumors on penny stocks in hopes of making a quick buck. Some follow scammers on twitter who sell newsletters full of bogus stock tips. Some cant get around the psychology of trading, and thus close out losing positions late and winning positions early (or never at all) [I myself use to do this!!]. I am certain 99% of retail traders cant beat the market, because most of them, to be frank, put less effort into deciding what to trade than in deciding what to have for lunch. Even though your pension funds presentation is correct with respect to retail traders, it is largely irrelevant as professionals managing your money should not fall into any of these traps.
2) I call day traders active traders, but its likely not what your pension fund was referring to. Day trading is an entirely different animal to long or medium term investing, and thus I also think the typical performance is irrelevant, as they are not going to manage your money like a day trader anyway.
3,4,5) So the important question becomes, do active funds lose 99% of the time compared to index funds. NO! No no no. According to the WSJ, actively managed funds outperformed passive funds in 2007, 2009, 2013, 2015. 2010 was basically a tie. So 5 out of 9 years. I dont have a calculator on me but I believe that is less than 99%!
Whats interesting is that this false belief that index funds are always better has become so pervasive that you can see active funds have huge outflows and passive have huge inflows. It is becoming a crowded trade. I will spare you the proverb about large crowds and small doors.
Also, index funds are so heavily weighted towards a handful of stocks, that you end up becoming a stockpicker anyway. The S&P is almost indistinguishable from AAPL. Earlier this year, only 6 stocks were responsible for over 100% of gains in the NASDAQ index. Dont think FB has a good long term business model, or that Gilead and AMZN are a cheap buy? Well too bad if you bought QQQ, because those 3 stocks are your workhorses now. See here
6) That graphic is for mutual funds but your pension fund may have also been including hedge funds in their 99% figure. While many dont beat their own benchmark, its less than 99%. And there are reasons for it. Many have investors that are impatient. Fortress just had to close one of its funds, whose bets may actually pay off years from now, but too many people wanted their money out. Some hedge funds also have rules, eg long only, which can really limit your performance. While important to be aware of this, that placing your money with a hedge fund may not beat a benchmark, that does not automatically mean you should go with an index fund.
So when are index funds useful? When you dont want to do any thinking. When you dont want to follow market news, at all. Then they are appropriate.