as I was searching already several times for this information, I put it now here

QLA available since 2012/12/12, publicly available since 2013/09/01 and official alerts since 2014/03/18

# total	#	Date, Time	Source	additional info
1	1	10.6.2014 0:57	Mrk 501	3-4 CU, for night of 8./9.6.2014
2	2	19.6.2014 3:32	Mrk 501	~ 3 CU
3	3	21.6.2014 2:46	Mrk 501	3-4 CU, only 1 bin above limit
4	4	24.6.2014 2:17	Mrk 501	> 5 CU, triggered HESS Atel #6268
5	5	28.7.2014 0:28	Mrk 501	> 5 CU, missed other alerts around this date
6	6	22.8.2014 1:12	Mrk 501	~ 3 CU
7	1	4.12.2014 1:29	Mrk 421	3-4 CU, for the night of 2./3.12.2014
8	1	19.10.2015 2:13	1ES 1959+650	1-2 CU for 20-30 min
9	2	4.11.2015 22:13	1ES 1959+650	1 CU for 10-20 min
10	3	15.11.2015 21:46	1ES 1959+650	1 CU for 10-20 min
11	2	17.12.2015 6:29	Mrk 421	3 CU for 20 min, 2 CU for > 1.5h, not ideal weather
12	4	29.4.2016 11:03	1ES 1959+650	confirmation of bright emission, indication for flux increasing with time
Atel 1	1	30.4.2016 00:54	1ES 1959+650	Atel #9010 (with Fermi-LAT, MAGIC, VERITAS)
13	5	30.4.2016 7:56	1ES 1959+650	update, similar flux to last night
14	6	17.5.2016 6:21	1ES 1959+650	0.5-1 CU, referred to in Atel #9070
15	7	6.6.2016 9:46	1ES 1959+650	> 1CU, referred to in Atel #9121, highest flux so far from the source
16	8	7.6.2016 5:35	1ES 1959+650	> 1CU with 4 sigma in first bin then decrease
17	9	8.6.20168:43	1ES 1959+650	update, still > 0.5 CU with 6 sigma for the whole night
18	10	9.6.2016 6:20	1ES 1959+650	> 0.5CU with > 4 sigma so far and one 20 in bin > 3 sigma
19	11	10.6.2016 6:44	1ES 1959+650	> 1CU with three bins > 3 sigma and > 6 sigma for total night so far, flux again as high as 4 nights ago (highest flux)
Atel 2	1	10.6.2016 19:00	Mrk 421	Atel #9137 (with HAWC and Swift)
Atel 3	2	10.6.2016 22:04	1ES 1959+650	Atel #9139
20	12	11.6.2016 6:44	1ES 1959+650	1-1.3 CU with three bins > 3 sigma and ~ 6 sigma for total night so far, highest flux so far

short summary:

Source	trigger limit	# alerts	# atels
Mrk 501	3 CU	6	-
Mrk 421	3 CU	2	1
1ES 1959+650	0.5 CU, 3 sigma	12	2