Table 2. Areas where yields are increasing and not increasing estimated using two different yield datasets.

Crop	% of the harvested area in 2000
	Reference [4]		R12		I14
	NIa	IMb	NI	IM	NI	IM
Maize	30	70	25–29	68–75	21–23	64–70
Soybean	24	76	17–21	71–83	21–24	68–74
Rice	38	63	32–33	66–68	22–28	53–67
Wheat	39	61	39–40	60–61	33–36	35–54

^a Yields not improving (= yields never improved + yields stagnating + yields collapsed).

^b yields improving (= yields increasing rapidly + yields increasing moderately + yields increasing slowly).