calculateAttendanceRateForMember

    public function calculateAttendanceRateForMember(Member $member)
    {
        $memberJoinedDate = $this->membership->getJoinedDate($member);
        $oneYearAgo = (new \DateTime('now'))->modify('-1 year');

        if ($memberJoinedDate < $oneYearAgo) {
            // The member is part of the organization for more
            // than a year, count only the meetings in the last year

            $calculateFrom = $oneYearAgo;
        } else {
            // Otherwise, count the meetings that happened since
            // the member joined

            $calculateFrom = $memberJoinedDate;
        }

        $calculateTo = new \DateTime('now');

        $attended = $this->meetings->countAttendanceForMember($member, $calculateFrom, $calculateTo);
        $total = $this->meetings->countMeetingsInPeriod($calculateFrom, $calculateTo);

        if ($total == 0) {
            return 0;
        }

        $rate = ($attended / $total) * 100;

        return (int)round($rate, 0);
    }