You can see the error bars at the end, can't you? Do you know about standard deviation? They are both within these range so you can not say it is a 10 percent increase. Also do you see a 10 percent increase for CBD? It is a high-CBD, low-THC variety so at such small differences of 0,03 % points (!) you have always measurement errors or deviations etc that have more impact than they would have for maybe a 10 % THC variety etc.
In hope to make it a bit more clear what i mean by standard deviation:
So for a simplified example you want to weigh out 1 gram of a substance with a scale that has 0,1 g readout. At 0,95 g the scale will show 1 g and at 1,04 g it would also show 1 g.
(Besides the fact that it could also show 1 g while it actually being 0,9 g etc because of the given accuracy/measurement repeatability, but to simplificate this example it should not matter here).
That is a deviation of +4/-5 % and you can not for sure say it is 0,95 or 1 or 1,04 g or anything between. It MAY be that it is but it may also be not. That is measurement uncertainty.
If you want to weigh out 10 g on that same scale it could be 9,95 or 10,04 which corresponds to +0,4/-0,5 %, a much smaller deviation in relation to the weight. Because of this you use more precise scales for measuring tiny amounts to have an adequate accuracy btw.
For sure they don't have such inaccurate scales in their lab, but there are many other factors that play a role for the end result like the accuracy of the gas chromatograph, which part and how much of a plant was used, how accurate the growing environment is and so on. There are many things playing a role that all have possible deviations by nature or instrumental errors that sum up or influence the final accuracy of the resulting data.
As a serious scientist you have to give these deviation values because they are important for the end result. To get more certainty you have to repeat the experiment over and over (and preferably by other research teams, too) and because of this it is not sufficient to only run an experiment once or twice for example because the results are just too uncertain to be significant.
This is statistics, often complex to calculate (while there are programs doing that after you input all the data), but this is how science works.
So while it COULD be that THC is 10% higher, it could also be lower according to the error bars.
To be honest i don't know how many replicates they have done but remember those people are professionals who know what they do and i don't think they would draw such conclusions without feeling certain. Sooner or later they will hopefully release their data in a scientific journal and it will get peer reviewed by others.
In the end i would trust scientists like them more than any fertilizer company that only make wild claims without showing any data or research to back up their claims. Why oh why do they not? Either they haven't done any or their data doesn't show what they claim.
Whatever, to this day i haven't seen ANY SOLID SCIENTIFIC data from a cannabis nutrient company that shows evidence. If PK boosters (or even flowering nutrients) would really have such a benefit as they say, it should be nothing to back up their claims through research and showing solid data. WHY ARE THERE NONE? NOT A SINGLE ONE !
(Besides some marketing-painted fantasy scaled pretty diagrams lol)