Purging elements from the map if it reaches a memory size limit

Question

I have implemented a LRU cache using ConcurrentLinkedHashMap. In the same map, I am purging events if my map reaches a particular limit as shown below.

I have a MAX_SIZE variable which is equivalent to 3.7 GB and as soon as my map reaches that limit, I am purging events from my map.

Below is my code:

import java.util.concurrent.ConcurrentMap;
import com.googlecode.concurrentlinkedhashmap.ConcurrentLinkedHashMap;
import com.googlecode.concurrentlinkedhashmap.EvictionListener;

// does this really equal to 3.7 GB?
public static final int MAX_SIZE = 20000000; //equates to ~3.7GB with assumption that each event is 200 bytes AVG

public static EvictionListener<String, DataObject> listener = new EvictionListener<String, DataObject>() {
    public void onEviction(String key, DataObject value) {
        deleteEvents();
    }
};
public static final ConcurrentMap<String, DataObject> holder = new ConcurrentLinkedHashMap.Builder<String, DataObject>()
            .maximumWeightedCapacity(MAX_SIZE).listener(listener).build();

private static void deleteEvents() {
    int capacity = MAX_SIZE - (MAX_SIZE * (20 / 100));
    if (holder.size() >= capacity) {
        int numEventsToEvict = (MAX_SIZE * 20) / 100;
        int counter = 0;
        Iterator<String> iter = holder.keySet().iterator();
        while (iter.hasNext() && counter < numEventsToEvict) {
            String address = iter.next();
            holder.remove(address);
            System.out.println("Purging Elements: " +address);
            counter++;
        }
    }
}

// this holder map is used in below method to add the events into it.
// below method is being called from some other place.
public void addToHolderRequest(String key, DataObject stream) {
    holder.put(key, stream);
}

Below is the maven dependency I am using for this:

<dependency>
    <groupId>com.googlecode.concurrentlinkedhashmap</groupId>
    <artifactId>concurrentlinkedhashmap-lru</artifactId>
    <version>1.4</version>
</dependency>   

I am not sure whether this is the right way to do this? Does this MAX_SIZE really equates to 3.7 GB if events are of 200 bytes in average? Is there any better way to do this? I also have a background thread which call deleteEvents() method every 30 second.