Have a look at the SSD Statistics page of the device statistics log (-l smart). This has one "Percentage Used Endurance Indicator" value, which is 5 for three of these disks, and 6 for one of them. So based on that, the drives still have ~95% of their useful life left.
As I understand it, the values in the device statistics log have standardized meanings that apply to any drive model, whereas any details about SMART attributes (as in the meaning of a particular attribute or any interpretation of its value apart from comparing the current value with the threshold) are not. So absent a data sheet for this particular drive documenting how to interpret attribute 177, I would not feel confident interpreting the normalized value as a percentage; all you can say is that the current value is > the threshold so the drive is healthy.