In 2002 the Average Sunday Attendance (ASA) for the domestic dioceses of the Episcopal Church was 846,640. In 2012 the domestic ASA was 640,142; a decline of 206,498 or 24 per cent over ten years. The 2012 totals do not account for the session of the Diocese of South Carolina, which would subtract an estimated 25,000 from the church’s baptized membership and 11,000 from its ASA.

Baptized membership in the Episcopal Church of the USA declined by 29,679 in 2012 to 2,066,710, the Episcopal Church reported on 31 October 2013.

Statistics released by national church showed Average Sunday Attendance declined steadily across the church as well 2.6 per cent in 2012, with 679,923 Episcopalians in church on Sundays.

Growth in baptized membership was seen in 33 domestic dioceses: Alaska; Arkansas; Atlanta; California; Central Florida; Chicago; Colorado; East Tennessee; El Camino Real; Florida; Fond du Lac; Hawaii; Idaho; Iowa; Kansas; Maryland; Mississippi; Missouri; Montana; Navajoland; North Carolina; North Dakota; Northern California; Oklahoma; Pittsburgh; San Joaquin; Tennessee; Texas; Upper South Carolina; Washington; West Tennessee; Western Massachusetts; Western New York.

However, Average Sunday Attendance (ASA) grew in only ten domestic dioceses: Alaska, Arkansas, Fond du Lac, Nevada, Northern California , Northern Indiana, Oregon, Pittsburgh, Rio Grande, and San Joaquin.

The Diocese of Nevada saw the greatest percentage and numeric growth in attendance of any diocese, 6.9 per cent or 165 people, while the Diocese of Ohio had the steepest decline: ,150 or 14.4 per cent.

In 2002 the ASA for the domestic dioceses of the Episcopal Church was 846,640. In 2012 the domestic ASA was 640,142; a decline of 206,498 or 24 per cent over ten years. The 2012 totals do not account for the session of the Diocese of South Carolina, which would subtract an estimated 25,000 from the church’s baptized membership and 11,000 from its ASA.

Source