So the remaining 53% didn't experience a delay that was eligible for compensation or no delay at all?
The remaining 53% didn't experience any delay at all, or only a delay that wasn't eligible for Delay Repay compensation - or possibly just don't remember any such delay.
Note that 53% is the original proportion of survey respondents who didn't experience an eligible delay. The data was then weighted so as to be more representative of all rail users in terms of age, gender and region/nation of residence, e.g. if 1% of the survey responses were from Scottish males aged 45-54, but they are believed to make 3% of all rail journeys, each such response was counted as one and a half.
After that adjustment, 52% had experienced an eligible delay, so the proportion who didn't experience any delay at all, or only a delay that wasn't eligible for Delay Repay compensation, would fall to 48% (page 25).
NB the example is my understanding of how the weighting was done - it's not precisely explained, but must be that or something very like (page 24).