Read the following data showing declining trend in Sex-Ratio for all age groups and that of child sex-ratio during the 20th century in India and answer the questions that follow—

The Declining Sex-Ratio in India, 1901-2001

Year	Sex-ratio (All age groups)	Variation over previous decase	Child-sex ratio (0-6 year)	Variation over previous decade
1901 1911 1921 1931 1941 1951 1961 1971 1981 1991 2001	972 964 995 950 945 946 941 930 934 927 933	__ -8 -9 -5 -5 +1 -5 -11 +4 -7 +6	__ __ __ __ __ __ 976 964 962 945 927	__ __ __ __ __ __ __ -12 -2 -17 -18

Sex-ratio = number of females per 1000 males.

(i) Why has been the column of child-sex ratio left blank upto 1961 CE in this table?

(ii) What may be the reason for growth in sex ratio (all age groups) in 2001 CE?

(iii) Find out why would child sex ratio have declined 18 point when sex ratio (all age groups) had increased to 6 points in 2001?

(iv) Mention why the trends of the last four decades have been worrying?