Mining difficulty on the Bitcoin network has taken its steepest upturn in almost a year, surging by over 14% to hit 9.06 trillion
Source: https://cointelegraph.com/news/bitcoin-mining-industry-is-booming-as-difficulty-soars-14-to-new-high
Bitcoin Mining Industry is Booming as Difficulty Soars 14% to New High
July 12, 2019
CoinTelegraph