title: How can I change the default title “Number at risk” in the risk table in survminer
body: <p>I'm running a survival probability (Kaplan-Meier) curve using the survminer R package. I'm setting on the risk table, however, I'd like to change the default title "Number at risk". How could I do it? </p>
  
  <p>I'm using the following code:</p>
  
  <pre><code> survAL &lt;- survfit(Surv(time, death) ~ AL.Factor, data = wave1)
  
   ggsurvplot(survAL, legend.title = "Allostatic Load", legend.labs = c("Low", 
  "Mid", "High"), ylim = c(0.90, 1.0), conf.int = TRUE, pval = TRUE, 
   xlim = c(0,10), xlab = "Time in years", ylab = "Survival Probability", 
   break.time.by = 2, ggtheme = theme_light(), risk.table = TRUE, 
   risk.table.col = "strata",  data = wave1)
  </code></pre>