Both can be right. It is a weighted average so unless you know...

Both can be right. It is a weighted average so unless you know the milk intake you can't check it. Opening would likely be based on the previous year's intake - but every year is different. Half year will likely be quoted on the half year actual intake/payment and an estimate for the next six months. Milk payment is different month to month (you can get the contract on the web site), so if someone produces more milk than forecast in higher paying months the weighted average goes up - and vice versa.