Don't calc the stats if there's no data

Add a % of users in the room that participated in reviewing today.

source/SOCVR.Chatbot/ChatbotActions/Commands/Stats/RoomEffectiveness.cs

@@ -35,6 +35,12 @@ public override void RunAction(Message incomingChatMessage, Room chatRoom)
                     .Where(x => x.ReviewedOn.Date == DateTimeOffset.UtcNow.Date)
                     .ToList();
 
+                if (reviewsInDbToday.Count == 0)
+                {
+                    chatRoom.PostReplyOrThrow(incomingChatMessage, "I don't have enough data to produce those stats.");
+                    return;
+                }
+
                 var reviewerCount = reviewsInDbToday
                     .Select(x => x.ReviewerId)
                     .Distinct()
@@ -44,7 +50,9 @@ public override void RunAction(Message incomingChatMessage, Room chatRoom)
 
                 var percentage = Math.Round(reviewItemCount * 1.0 / stats.ReviewsToday * 100, 2);
 
-                var message = $"{reviewerCount} members have processed {reviewItemCount} review items today, which accounts for {percentage}% of all cv reviews today.";
+                var usersPercentage = Math.Round((double)reviewerCount / chatRoom.PingableUsers.Count(x => x.Reputation >= 3000));
+
+                var message = $"{reviewerCount} members ({usersPercentage}% of this room's able reviewers) have processed {reviewItemCount} review items today, which accounts for {percentage}% of all CV reviews today.";
 
                 chatRoom.PostReplyOrThrow(incomingChatMessage, message);
             }