In reply to Ann S:
I think my graph looks like a seismigraph during an earthquake .
Slow bumbly start ( 2 years at uni to break into Severe!), then a rapid jolt upwards (first E1 three years later) with a few aftershocks (first E2).
Big jolt downwards (when i discovered paragliding).
Next aftershock five years later (got back into climbing).
Bit of a plateau since then. Expecting the gentle side of the scarp slope to start kicking in a few years. Don't care though, it's been a ball :-D