Fairly good maths, IIRC I started the season with ~170 red packs, currently I have 156, which includes some pack-farming on iPhone (this season I've concentrated less on farming in general - it's summer, and less farming efforts on reds, more on greens and $, since I went out of the Cup in round 1 meaning I've done more power training and had lower earning).
Based on all the anecdotal evidence around it looks like the Friendlies injury rate has gone up - though I'd also say the training injury rate may have dropped
Still a few days left in the season so this may change, but at the moment I've averaging an injury every 1.6 days - which is down on last season, but the same as the one before that