Second if else statement in JS is never executed [duplicate]

Using the following code I'm trying to calculate AK based on brutojaarloon. Even if the value of brutojaarloon exceeds 21430, the first else if statement is still executed.

I understand that if brutojaarloon is higher than 21430, it's also higher than 9921, but that's what the && is supposed to catch.

if (brutojaarloon < 9921) {var AK = brutojaarloon * 0.02812 ; }

else if (brutojaarloon => 9921 && brutojaarloon < 21430) 
{ var AK = ((brutojaarloon - 9921) * 0.28812) + 279; }

else if (brutojaarloon => 21430 && brutojaarloon < 34954) 
{ var AK = ((brutojaarloon - 21430) * 0.01656) + 3595; }