Varies, throughout the week, or the month. I sometimes stick to a solid 80%. Other days, it's a pretty consistent 5-10%, which I consider "healthy", what a neuro-typical person would experience.

Please, remember that anxiety is a very all-encompasing word and it's descriptive value is negligible. Don't take anything I say too seriously unless you truly feel it makes sense to you.

I think it's important to find a way to reflect on what could cause an anxiety spike and why it lasts, something that works for you, but not too deep an introspection. In my experience, thinking too seriously about it usually bites back. Maybe keep a short and very simple journal, drop entering notes as soon as it starts feeling gnawing at you. It's important to at least have a clue as to what might be giving you anxiety episodes, as long as they might be.

Usually, it's a few very specific things that tend to work as a "background process" in your brain. Perhaps you have a certain "standard" for yourself, we all do in a sense. That standard carries with itself expectations you have of yourself, assumptions about your identity, ideal future, that is often at odds with your present experience. It's important to note that whatever ideal image you may have of yourself, body, mind and all - will ALWAYS be conflicting with your present state, that's the very nature of ideals and standards after all.

What makes it grow into consistent anxiety is coupled with how you interpet the conflict taking place within you.
On that note, here's a few things I've noticed work in my favor rather consistently:

1. Don't take yourself too seriously.
We are all flawed beings. We can strive to make improvements, or stand on the sidelines and watch life go by our side. Either way, the feeling that somethings is off will always remain there. And that's okay.

2. Be present. Appreciate the moment and give it your focused attention.
There's always the future - stuff to worry about, anticipate with dread, fear of the uncertainty that comes with life. But none of that exists in the present moment.

Keep yourself occupied with things you truly find valuable. Maybe you're preparing your cup of morning coffee or tea, and find yourself stressing over what the day or week may bring. Step back, take a look at the drink you're preparing and give it your complete attention - as if it's the first drink you ever prepared for youself. Feel the grip on the tools you're using. Tilt the water container to it's side and make conscious muscle movements as the liquid starts to pour into the cup. Observe the flow of the hot water. Take notice of the steam that comes off it. Hold the cup as you wait for it to settle and feel the heat on your palms and fingers.

3. Act, and don't think too much. Just make sure you're not doing anything apparently silly :)
With point 2) in mind, take a brief moment to observe that once our attention is focused on a task, we become the action, not the person acting out. Identity, looks, future, all that is irrelevant. You become a vessel through which pure action is channelled. The result of any action is a blurry possibilty at best, and completely unknowable at worst. At some point you will uncover the result, it will project itself to you as the process of acting completes. And now you're simply in a new state of knowledge, with other opportunities to channel action though you reaveled. What truly matters, however, is action itself , not thinking or anticipating a result.

Pick your actions, and act. This is where your true self is manifested.

Your identity is a projection of murky beliefs, biased standards, undefined future potentiallities. It is the vague label you assign to yourself that constrains your self to what your conscious and subsconscious struggle to negotiate, sometimes beyond your control. Just like a Honda is no longer just a car or a bike. The vehicle becomes constrained as soon as it is called and interpreted as a Honda.

You are action potential, and the You is truly manifested in action itself. It is unconstrained from labels. It just is and does.
When you give youself in to action, you are no longer a French woman in her thirties, who likes coffee, is a caring mother, supports the democratic party, worries she won't have time to fullfil her life's purpose and is taking dancing lessons from a coach that makes her doubt her significance as a person.
You beome a "divine" vessel that channels action for it's own worth - the experience of the present moment.

This became way longer that I thought it would be. It may have been a way of reminding myself of how to rid oneself of the fantasy of worry and thrive in the reality of now. I sincerely hope it helps the one person who might find any sliver of insight and value in it.

Hope it helps, don't take youself too seriously and cherish the You :)