Your profile does not show where you are, so it is difficult to give good advice. These are the stats from my 2013 SV, built in January 2013, when it dropped the ninth bar.
AHr=36.81, SOH=56%, Hx=49.75%, odo=25,670 miles, QC=4 L1/L2=2242
The car does need to be driven regularly for the bar to drop. I drove mine very little during the summer of 2017, due to the range loss. After starting to drive it again (and fairly aggressively), the bar dropped after about a month.
If you are in a warmer climate, and you have confirmed the in-service date with Nissan (877-NO-GAS-EV), then you should have no problem getting the bar to drop by next July. It is still a gamble, but likely a risk work taking, depending on the price of the car.
The SOC does not affect the AHr, SOH, and Hx readings. Based on the picture shown, the cells are in serious need of balancing. This is done by charging to 100%. I would do that every day, and watch the stats, while deciding if you are going to keep the car.
Driving the car regularly (and aggressively), charging to 100% during the hottest part of the day, and leaving it at 100% when not driving, are tactics used to help push it along to get the 9th bar to drop.
2013 Leaf SV - Cayenne Red - QC Port - LED Headlights