Restrictions on custom fields

Restrictions on custom fields

Legend in the top of field pages say you can add up to 130 custom fields. 
But I get the error message while creating some:  " Custom Currency & Percentage Fields exceeds the limit of 15. Hence cannot be created."
When I changed the field to decimal, the same message was displayed. 

What are the restrictions on the fields you can create?

Can I only create 15 numeric fields of any type?

Thanks