The TOEIC score

It occurs to find books labeled the TOEIC score as general level of a skil.

You could use it as one of standards for choosing. TOEIC score

・Score 400s:Short sentenses Lebel a junior high school student manages to read

・Score 500s:Almost short sentenses Lebel the first grade of a high school students manages to read

・Score 600s:Many long sentenses Lebel graduated students of a high school can read easily

・Score 700s:Long sentenses is a main Lebel many hours make graduated students of a high school possible to read

・Score 900s:Lebel a parson near a native speaker can read
(A standard explained using a grade of students is the above,but it doesn't apply.)

For example, I think a parson can read 700s books of a field whose much knowledge he has who doesn't have so much English skil.

It is more useful for reading to have much vocabulary than to know many grammers.

Having been a book of well-knowing field, he can surmise meaning of sentenses from words he knows however poor he is at composition of sentenses.

So you should challenge a bit difficult books whose field you're interested in acording to TOEIC score and so on.