Not much can be inferred from this statistic. It is not clear how many of these wallets are owned by individuals and how many of them are owned by companies such as exchanges and online casinos. Secondly, there is a chance that the same individual is in the possession of multiple wallets. For someone in possession of
BTC100 or more, it is not unusual to have as many as a dozen different wallets. And another thing is the existence of lost coins. There are coins, which can never be spent because no one is having the private key (Satoshi's stash of
BTC980,000 is a perfect example). The only information regarding the Bitcoin wealth distribution comes from rpietila's thread here (but it is not very reliable):
https://bt.irlbtc.com/view/316297.0