Correct tense after "in recent years"
1) In recent years, the costs of eating were continually decreasing
2) In recent years, the costs of eating have been continually decreased

Question

Answer

The second one, for the reason Luis stated, except it should be decreasing, not decreased.

Answer

The second one is correct. Because you have to use Present perfect tense to talk about events that star in the past and continue happening. For example, Costs of eating was decreasing and it still is.

Regards!

Answer

2) In recent years, the costs of eating have been continually decreased

Present Perfect Passive Voice