Chlorine has two stable isotopes with masses of 34.97 amu and 36.97 amu. What is the relative abundance of chlorine with a mass of 34.97 amu?

Chlorine has two stable isotopes with masses of 34.97 amu and 36.97 amu. What is the relative abundance of chlorine with a mass of 34.97 amu? The average atomic weight of Chlorine is 35.453 amu. (Use correct amount of significant figures)