The oil in Cambodia has low decrease if comparing to the world decrease

After reading the post of Kohsantepheap Newspaper about the oil cost in the world and Cambodia, the decrease of the petrol price is too low in Cambodia.

The world's recent high oil cost around 140$ and now is only 97$ per barrel.

In Cambodia, the decrease of the petrol is too slow and not much, it's just only 150 riels (0.0365 $) and the price I saw this morning for normal petrol is 5100 riels (1.243$), for super is 5200 riels (1.268$).

When the oil in the world cost around 140, the petrol price in Cambodia is 5600 riels (1.365 $ for normal petrol) and 5700 - 5750 riels (1.39$ for super).

How far different is it?