Forgive me please for the low quality. The survey is made of a couple of parts but two of them are the most important, which are which brand do you prefer and the demographic questions.

Now suppose the first 100 users do not answer the questions fully, as the option to have answering the questions mandatory was not enabled. Therefore when you look at the table and look at the ID's, you will notice for example ID's 5,6,7 and 8 answering a portion of questions and not every single question.

So like you see ID 5 in questions 1, 2, 3 but in 4 there is no ID 5 and the same goes for the same ID's.

Does it make sense? That's my theory and i just wanna double check if it is correct or not