August saw my first yarn purchase in over 2 years when I needed to buy some additional yarn to finish the following sweater (which used a total of 1,834 yards of yarn):

http://www.ravelry.com/projects/fak/krone
That added 374 yards to my stash (before finishing the sweater).
I also carded and then spun some alpaca fibre into 348 yards of light fingering weight yarn, losing some of the fibre along the way (I started with 100g but ended up with 87g). There was a lot of grease in the fibre which led to some gentle felting whilst washing it out, but I’m pretty happy with the end result.

http://www.ravelry.com/people/fak/handspun/cotswolds-alpaca
Total monthly yarn out: 1,834 yards, 367g
Total monthly yarn in: 722 yards, 162g
Net monthly yarn decrease: 1,122 yards, 205g
Monthly fibre stash reduction: 100g.
Total yarn out ytd: 12,769.5 yards, 4,507g
Total yarn in ytd: 13,750 yards, 3,180g
Net yarn increase ytd: 980.5 yards, (1,327)g
Fibre stash reduction ytd: 3,050g.