{ 
        if ( NR <= 2 ) { next } # skip first 2 lines
        tab_age[$2]+=$3
        tab_cpt[$2]++
}
END { 
        for ( genre in tab_age ) { 
        print genre, " : ", "Moy :", int(tab_age[genre]/tab_cpt[genre]), "ans", "nb :", tab_cpt[genre] 
        }
}