Totalling returned values from functions php

I am using this to pull out some facebook data from a CSV

https://github.com/Maatwebsite/Laravel-Excel

 public function lifetime_likes_by_gender_and_age_f18_24() {
        $result = $this->reader->select(array('lifetime_likes_by_gender_and_age_f18_24'))->get();
        retu  (int) $result->last()->sum();

    }

    public function lifetime_likes_by_gender_and_age_f25_34() {
        $result = $this->reader->select(array('lifetime_likes_by_gender_and_age_f25_34'))->get();
        retu  (int) $result->last()->sum();;
    }

 public function lifetime_likes_by_female() {        
retu  $this->lifetime_likes_by_gender_and_age_f18_24() +  $this->lifetime_likes_by_gender_and_age_f25_34();
}

The problem is the first value is retued as 12 the second is 112. So the answer should be 124 but it is retuing 136 which suggests it is doubling up the first value.

Any reasons why and how I can fix it?