Bigger container ships bring in more containers into Singapore but with fewer port calls.

http://www.seatrade-maritime.com/news/asia/box-volumes-at-singapore-port-increase-8-5-in-june.html

Singapore increases its container volume by 8.5% at 2.6m TEU in June 2017 compared to 2016.  However, the number of ships' calls drop 3.8% month on month to 3378 ships.

http://www.businesstimes.com.sg/energy-commodities/singapore-june-marine-fuel-sales-fall-to-their-lowest-this-year

This conundrum is caused by larger container ships which can carry more TEUs.  Therefore, our containers increase but the ship port calls drop which affects the bunker sales.