I will suggest that the ratio of testing time/effort over development time/effort should be getting larger over time.

I'll assert that analysis and requirements definition is a process of understanding what is really needed and stating that in a clear and understandable manner. Similarly, Testing is a process of making sure that what you have is fit for purpose. Both of these are likely to take a significant time for any system that is non-trivial. The size of these is controlled by the problem-space of the software. Development is different. The use of Open Source code, reuse of components and modern development tools should mean that the development needed to solve a particular problem should be reducing over time.

On that basis I we could suggest that over time a ratio of test time over development time could be used as a performance indicator of the maturity of the development approach. The bigger the better.