		Conditioned		Total
		Yes = +1	No = +0	Total
No Condition	Yes =+1	c = (₀W_t − a)	N − _RU_t − ₀W_t + a	N − _RU_t
No Condition	No = +0	a	b = (_RU_t − a)	_RU_t
	Total	₀W_t	N - ₀W_t	N