He's doing it in fewer games but he's also part of the self proclaimed best team in Premier League history, and in a team that is geared to make chance after chance for him. He's taken the most shots per game in the league of any player and has been in the top 2 in that regard every year since he returned to England. His goal statistics are no surprise.
It also wasn't a surprise that since January when the goals dried up his performances fell off a cliff. I said many pages back multiple times that underneath the goals was an extremely ordinary footballer, and I think this half a year has really shown that. He's a player who can produce great moments but he isn't a great footballer. He's a perfect fit for Klopp's system and they truly get the best out of him.