par(mfrow=c(1,2))
plot(prop_model, select=1, scale=0, shade=TRUE)
abline(h=0)

plot_smooth(prop_model, view="x1",main="")
(diff <- find_difference(out$fv$fit, out$fv$CI, xVals=out$fv$x1))
addInterval(0, lowVals=diff$start, highVals = diff$end, col='red', lwd=2)
abline(v=c(diff$start, diff$end), lty=3, col='red')
text(mean(c(diff$start, diff$end)), 2.1, "sign. more \n success", col='red', font=3)