I've been wondering about this idea for and while and would love to get your input -

How much do you think magic changes - as in, how many new spells and new treatments and such are being invented? Are old spells that were once really prevalent being replaced with newer more "efficient" ones?

The wizarding world seems to be somewhat slow changing, but does this apply to magic, too? What is the state of new magical "technologies?"

Any comments are greatly appreciated.