% Difference of Close from the highest Close for S&P 500

The highlighted is the  highest Close which happened in September 2018. Source: finance.yahoo.com

Date	Open	High	Low	Close	Volume	% Difference from highest Close	Data is
11/1/17	2,583.20996	2,657.73999	2,557.44995	2,584.84009	95 Billion	11.2952	Monthly
12/1/17	2,645.10010	2,694.96997	2,605.52002	2,673.61011	65 Billion	8.2489	Monthly
1/1/18	2,683.72998	2,872.87012	2,682.36011	2,823.81006	77 Billion	3.0944	Monthly
2/1/18	2,816.44995	2,835.95996	2,532.68994	2,713.83008	80 Billion	6.8686	Monthly
3/1/18	2,715.21997	2,801.89990	2,585.88989	2,640.87012	76 Billion	9.3724	Monthly
4/1/18	2,633.44995	2,717.48999	2,553.80005	2,648.05005	70 Billion	9.1260	Monthly
5/1/18	2,642.95996	2,742.23999	2,594.62012	2,705.27002	76 Billion	7.1624	Monthly
6/1/18	2,718.69995	2,791.46997	2,691.98999	2,718.37012	77 Billion	6.7128	Monthly
7/1/18	2,704.94995	2,848.03003	2,698.94995	2,816.29004	65 Billion	3.3525	Monthly
8/1/18	2,821.16992	2,916.50000	2,796.34009	2,901.52002	69 Billion	0.4276	Monthly
9/1/18	2,896.95996	2,940.90991	2,864.12012	2,913.97998	62 Billion	-	Monthly
10/1/18	2,926.29004	2,939.86011	2,603.54004	2,711.73999	91 Billion	6.9403	Monthly
11/1/18	2,717.58008	2,815.14990	2,631.09009	2,760.16992	80 Billion	5.2783	Monthly
12/1/18	2,790.50000	2,800.17993	2,621.53003	2,695.94995	14 Billion	7.4822	Monthly
12/3/18	2,790.50000	2,800.18000	2,773.38000	2,790.37000	4 Billion	4.2420	Daily
12/4/18	2,782.43000	2,785.93000	2,697.18000	2,700.06000	4 Billion	7.3412	Daily
12/6/18	2,663.51000	2,696.15000	2,621.53000	2,695.95000	5 Billion	7.4822	Daily

Box chart representation