There were specific periods for some price levels: the level 0.05 usd/BTC existed only in the 3th quarter of 2010, the level 1 usd existed only in the first part of 2011, the level 100 usd existed only in 2013, the level 2000 usd existed only in the middle of 2017... but since the 3th quarter of 2017 every price level has emerged repeatedly (more than just once).