1 to 10 is a starting point for dosing, there is no "normal" amount
My ratios vary between 1:6 and 1:8.5 currently, however I know I used to be on 1:5 (ie what you're on by the sounds of things) for quite a long time and I was normally verging on underweight at that point.
Basically ratios can change, and don't assume 1:10 is what its supposed to be for everyone, it's not, whatever works for you is what you need
May just be as you're getting slightly older (no-one can stop the passage of time right), might be due to slightly more weight, might be that the weather has gotten better, might be that the moon was shining brighter, ie it could be anything.