How to add a trendline to a log graph when x=0?

Hello,

I tried to plot my data (attached) and it looks like a log graph. I wanted to add a trendline, but it is not possible since the data starts at x = 0. At x = 0, it has a value (y-axis) and this is where the percentage of a substrate is 100%.

How may I plot the graph if I want to have a trendline equation? Should I start plotting at the second reading i.e. after x =0? If so, how I may extend the trendline so that the y-intercept is the y-value of x = 0?

Thanks for your response, I really appreciate it.