Unfortunately this webinar is at my 4AM. I have a question about the drive data here - I've downloaded the Q3 data and it looks like there are 59 drives listed

Unfortunately this webinar is at my 4AM. I have a question about the drive data here - I've downloaded the Q3 data and it looks like there are 59 drives listed as at 2020/9/30 for the ST16000NM001G (and the same at 2020/7/1). I compared it with the April 1 data set and it which appears to have 60. Serial number ZL202NFZ appears to be dropped in the later version and serial number ZL202400 seems to not be reading as at April 1 but is available at a subsequent date. Just curious what's going on here! I recently received one of these and the backblaze drive data was very helpful with my evaluation.