Wheat productivity

the productivity of wheat in 2011 in haryana is 4650 kg per hectare whereas in 1950-1951, it was 663 kg per hectare.
4650/ 663= 7.01357

and 7^(1/60) = 1.03296
so, that means the wheat  productivity has grown up by 3.3 percent every year in last 60 years.