Why do you want to leave your Current Employer?

the main reason to leave my current employer is less salary 

 I have been at my company for six years now and have learned a lot from working with some amazing sales and marketing force people.  I worked my way up to regional GCC sales & Marketing manager and my region has beaten our sales projections by at least 35 % each quarter since. However, I am starting to feel like I need some new challenges. This position really appeals to me because it would allow me to manage a bigger team and sell more innovative products, Time for future career.