Examples of ordered set aggregates in Postgres.

SELECT round(avg(pie)::numeric, 2),
       percentile_cont(array[0.25, 0.5, 0.75, 0.95]) WITHIN GROUP (ORDER BY pie) AS percentiles
FROM player_stats_advanced
WHERE permode = 'pergame';

round	percentiles
0.08	{0.061,0.084,0.107,0.145}

SELECT season,
       round(avg(pie)::numeric, 2),
       percentile_cont(array[0.25, 0.5, 0.75, 0.95]) WITHIN GROUP (ORDER BY pie) AS percentiles
FROM player_stats_advanced
WHERE permode = 'pergame'
GROUP BY 1;

season	round	percentiles
1996-97	0.08	{0.06,0.083,0.106,0.146}
1997-98	0.08	{0.0595,0.084,0.108,0.1441}
1998-99	0.08	{0.05275,0.085,0.109,0.156}
1999-00	0.08	{0.061,0.084,0.1065,0.1431}
2000-01	0.08	{0.059,0.081,0.105,0.148}
2001-02	0.08	{0.06275,0.085,0.104,0.1401}
2002-03	0.08	{0.06075,0.084,0.106,0.14365}
2003-04	0.08	{0.061,0.085,0.10675,0.137}
2004-05	0.08	{0.058,0.084,0.105,0.14585}
2005-06	0.08	{0.059,0.081,0.103,0.152}
2006-07	0.08	{0.05925,0.0835,0.103,0.145}
2007-08	0.08	{0.06,0.083,0.1055,0.1465}
2008-09	0.09	{0.063,0.085,0.109,0.1468}
2009-10	0.09	{0.065,0.086,0.105,0.147}
2010-11	0.08	{0.063,0.084,0.107,0.1415}
2011-12	0.08	{0.063,0.087,0.108,0.1452}
2012-13	0.08	{0.062,0.085,0.108,0.14265}
2013-14	0.08	{0.063,0.086,0.105,0.141}
2014-15	0.08	{0.064,0.087,0.1095,0.1455}
2015-16	0.09	{0.068,0.087,0.109,0.1434}