Confusing?
Sure. The problem is that each manufacturer interprets SMART data differently.
Take a look at the tests I did just now on my SSD using the Sandisk SMART utility.
SMART ID No. 5 shows a RAW count of 1. This means one bad sector has been reallocated.
SMART ID No. 232 "Spare Blocks Remaining" shows a RAW count of 99, which means 99% spare blocks remaining.
Now compare the SMART ID No. 5 result running WD SMART test on the same Sandisk SSD.
It shows a Current value of 100. The Sandisk test for SMART ID No. 5 gave a value of 1 (RAW number of bad sectors) while the WD SMART test for the same SMART ID No. 5 gave a value of 100 (% of replacement sectors remaining (100 instead of 99 is probably due to rounding)).