State the number of significant figures in the following measurements :
(i) `0.009 m^(2) " " (ii) 5.049 N m^(-2) " " (iii) 0.1890 g cm^(-3) " " (iv) 1.90 xx 10^(11) kg " " (v) 0.020800 m " " (vi) 5.308 J `