Beginner in regex

I am a beginner at Regex, I have a file containing the recordings in the following format:

  • I'm calling Ajay. I am 20 years old.
  • I'm calling George. I'm 44 years old.
  • I'm calling Nancy I'm 19 years old.
    There are 100 records of this type and I have to write a regex to match records of people under 20 years old.
    My Regex expression in: My name is [w].I am [0-20] years.
    Is it correct?