Track count of common zombies killed

/*
commonskilled.nut
author: Lee Pumphret
https://www.leeland.info

Skeleton script to track number of common zombies killed fairly accurately. De-spawns may get counted

@ https://www.leeland.info/trcoofcozoki.html
*/

ZombiesSpawned <- {}
ZombiesSpawnedCurrent <- 0
ZombiesSpawnedCount <- 0
ZombiesKilledCount <- 0
ThinkCount <- 0

function Think(){
   local  OurLastSeen = null
   local z
   local health = 0
   ZombiesCurrent <- 0
   ToDelete <- []

   try{ 
   while (z = Entities.FindByClassname(OurLastSeen,"infected")){
      health = z.GetHealth();
      if (health > 0 ){
           if (ZombiesSpawned.rawin(z) == false){
                //printl("new common "+z);
                ZombiesSpawnedCount++; // only record if new
            }
          ZombiesCurrent++
          ZombiesSpawned[z] <- health // save it 
      }
      OurLastSeen = z   
   }
   }catch(e){ // this exception handling probably not needed, but why not
    printl("Error:"+e);
    OurLastSeen = null
   }
   
   foreach (k,v in ZombiesSpawned){
        try { // this trapping is...
            v = k.GetHealth()
        }catch(e){
            v = -666
        }
        if (v <= 0){
            //printl("dead or invalid: "+v)
            ToDelete.push(k)
        
        }else{
            // it's alive, do what you want here
        }

   }   
   
   // cleanup
   while (ToDelete.len() > 0){
       delete ZombiesSpawned[ToDelete.pop()]
       ZombiesKilledCount++
       ZombiesCurrent--
   }
   ZombiesSpawnedCurrent = ZombiesCurrent 
   
   if (ThinkCount++ % 10 == 0){
        // print stats once a second
        print_stats()
   }
   
}


function print_stats(){
    printl("stats > Z_LIFETIME:"+ZombiesSpawnedCount+" CURRENT:"+ZombiesSpawnedCurrent+" KILLED:"+ZombiesKilledCount+" ERROR:"+(ZombiesSpawnedCount - (ZombiesCurrent+ZombiesKilledCount)));
}