The following table shows the production of food grains in a country over the five years.

Year	Production (in ten lakh tonnes)
	Wheat	Rice	Maize	Other grains
2016-17	650	250	200	450
2017-18	800	440	240	400
2018-19	680	390	220	500
2019-20	700	400	260	480
2020-21	640	440	300	520

The difference between the average production (in ten lakh tonnes) of wheat and maize over the years is: