The sex-ratio in Macao's population has not reached the point of imbalance, an official with the city's Statistics and Census Service (DSEC) said on Friday.

The number of female population in Macao has slightly exceeded that of the male while the number of the aging population remained at about 7 percent of the total over the past decade, said Cheng I Wan, deputy director of the DSEC, at a radio program of TDM, the largest broadcaster in Macao, when introducing the upcoming census.

To prepare for the 2011 Census, the DSEC launched a pilot survey on Friday, which is expected cover 8,000 housing units in a local neighborhood. Questionnaires will be distributed to collect information of the household involved.

Questionnaires to be used in the 2011 Census will be revised based on the results of the pilot survey, Cheng also said.

Macao's first census was carried out in 1867, when the local population stood at around 80,000, and the special administrative region (SAR) of China has by far conducted 14 censuses.

The number of Macao's population was estimated at 544,600 by the end of the second quarter this year, increasing by 2,200 from the previous quarter, according to the latest figures from the DSEC.