from datetime import datetime


def get_ages(pt_dob, examdates):
    """
    Calculates age as time passed by since DOB to EXAMDATE

    :param pt_dob: string - Date of birth of patient ("/%Y" format)
    :param examdates: list - Exam dates ("%m/%d/%Y" format)
    :return: list - Age at each exam date
    """


    age = []
    dob = datetime.strptime(pt_dob, "/%Y")

    for exam in examdates:
        examdate = datetime.strptime(exam, "%m/%d/%Y")
        delta = examdate - dob
        age.append(round(delta.days / 365.25, 1))

    return age