That's actually very good Rich, you've cut down so much and you've done so on so few ml's per day. I had to go through at least 5-6 ml's a day when I first quit smoking. Keep you devices with you at all times if possible and pick one of them up instead of a cig, you can do this.
Also if your juices are the same flavor or two compatible flavors you can mix the 24 and 12 together then split them between the two tanks to bring your nic level down to 18mg per ml, if you want.