On the other hand my linux Thinkpad has worryingly high numbers:

    Available Spare:                    100% 
    Available Spare Threshold:          10%
    Percentage Used:                    6%
    Data Units Read:                    123,210,825 [63.0 TB]
    Data Units Written:                 59,502,097 [30.4 TB]
    Host Read Commands:                 1,335,288,785
    Host Write Commands:                740,649,667
    Controller Busy Time:               3,494
    Power Cycles:                       3,069
    Power On Hours:                     5,339
    Unsafe Shutdowns:                   155