W2

I live in Kansas and work both in Kansas and in Missouri. On my W2 form in Box 1 is total wages for both states. In box 15 they have both states listed and in box 16 they have wages earned for each state and in box 17 for state tax they have $$ amounts listed for each withheld.  

I am wondering why I have to pay in large amount of state taxes for Kansas and made less than half of what i earned in Missouri and barely ow any state tax for Missouri?  
Am I getting taxed on total wages for both states ?  Help

Do I get taxed on adjusted gross income on Federal tax  form for KS state tax? 

For example: in Box 15 for State of Ks for state wages in box 16 is $15,000 and for state of Missouri is 34,000 should I not just get taxed on what I made in Kansas instead of being taxed on the total adjusted wages?