It probably doesn't mean much if anything, although you should always practice good backup.
It is generated by a few brands (including WD and Seagate) for link speed changes (6Gbps to 3Gbps) or bad data blocks encountered during routine operation. It is not one of the values that has a significant correlation to drive failure like reallocated sector counts (005), spin retry (010), or others like 197 increasing (pending sector count, i.e. bad sectors waiting to be reallocated). Just watch to see that it doesn't change much over time.
The value that you question, the E in 24E is a hexadecimal value so 0 to 9 then A to F (16 values, 0 to 15). So in base 10 the hexadecimal value E would be equal to 14.
For drives that run all the time,
HERE is a good quick read on the most important values that are highly correlated to drive failure.