Rewrite the sentence in passive form:
People add around 4000 new words to the English dictionary every year
1 )
Around 4000 new words added to the English dictionary every year
Around 4000 new words are added to the English dictionary every year
3 )
Around 4000 new words were adding to the English dictionary every year
4 )
Around 4000 new words had been added to the English dictionary every year