First published by Money Metals here: https://www.moneymetals.com/news/2018/07/31/top-gold-miners-production-decline-001587

Even though the gold price increased in 2018, the top gold miners production declined while costs continue to escalate. Output at three of the top gold miners in the world fell in the first half of 2018 compared to the same period last year. With rising costs due to higher energy prices, on top of decreasing production, the top gold miners free cash flow declined precipitously in 2018.